<fieldset>
  <legend>Occupation</legend>
  <select class="form-control dropdown" id="occupation" name="occupation">
    <option value="" selected="selected" disabled="disabled">-- select one --</option>
    <optgroup label="Healthcare Practitioners and Technical Occupations:">
      <option value="1">-  Chiropractor</option>
      <option value="2">-  Dentist</option>
      <option value="3">-  Dietitian or Nutritionist</option>
      <option value="4">-  Optometrist</option>
      <option value="5">-  Pharmacist</option>
      <option value="6">-  Physician</option>
      <option value="7">-  Physician Assistant</option>
      <option value="8">-  Podiatrist</option>
      <option value="9">-  Registered Nurse</option>
      <option value="10">-  Therapist</option>
      <option value="11">-  Veterinarian</option>
      <option value="12">-  Health Technologist or Technician</option>
      <option value="13">-  Other Healthcare Practitioners and Technical Occupation</option>
    </optgroup>
    <optgroup label="Healthcare Support Occupations:">
      <option value="14">-  Nursing, Psychiatric, or Home Health Aide</option>
      <option value="15">-  Occupational and Physical Therapist Assistant or Aide</option>
      <option value="16">-  Other Healthcare Support Occupation</option>
    </optgroup>
    <optgroup label="Business, Executive, Management, and Financial Occupations:">
      <option value="17">-  Chief Executive</option>
      <option value="18">-  General and Operations Manager</option>
      <option value="19">-  Advertising, Marketing, Promotions, Public Relations, and Sales Manager</option>
      <option value="20">-  Operations Specialties Manager (e.g., IT or HR Manager)</option>
      <option value="21">-  Construction Manager</option>
      <option value="22">-  Engineering Manager</option>
      <option value="23">-  Accountant, Auditor</option>
      <option value="24">-  Business Operations or Financial Specialist</option>
      <option value="25">-  Business Owner</option>
      <option value="26">-  Other Business, Executive, Management, Financial Occupation</option>
    </optgroup>
    <optgroup label="Architecture and Engineering Occupations:">
      <option value="27">-  Architect, Surveyor, or Cartographer</option>
      <option value="28">-  Engineer</option>
      <option value="29">-  Other Architecture and Engineering Occupation</option>
    </optgroup>
    <optgroup label="Education, Training, and Library Occupations:">
      <option value="30">-  Postsecondary Teacher (e.g., College Professor)</option>
      <option value="31">-  Primary, Secondary, or Special Education School Teacher</option>
      <option value="32">-  Other Teacher or Instructor</option>
      <option value="33">-  Other Education, Training, and Library Occupation</option>
    </optgroup>
    <optgroup label="Other Professional Occupations:">
      <option value="34">-  Arts, Design, Entertainment, Sports, and Media Occupations</option>
      <option value="35">-  Computer Specialist, Mathematical Science</option>
      <option value="36">-  Counselor, Social Worker, or Other Community and Social Service Specialist</option>
      <option value="37">-  Lawyer, Judge</option>
      <option value="38">-  Life Scientist (e.g., Animal, Food, Soil, or Biological Scientist, Zoologist)</option>
      <option value="39">-  Physical Scientist (e.g., Astronomer, Physicist, Chemist, Hydrologist)</option>
      <option value="40">-  Religious Worker (e.g., Clergy, Director of Religious Activities or Education)</option>
      <option value="41">-  Social Scientist and Related Worker</option>
      <option value="42">-  Other Professional Occupation</option>
    </optgroup>
    <optgroup label="Office and Administrative Support Occupations:">
      <option value="43">-  Supervisor of Administrative Support Workers</option>
      <option value="44">-  Financial Clerk</option>
      <option value="45">-  Secretary or Administrative Assistant</option>
      <option value="46">-  Material Recording, Scheduling, and Dispatching Worker</option>
      <option value="47">-  Other Office and Administrative Support Occupation</option>
    </optgroup>
    <optgroup label="Services Occupations:">
      <option value="48">-  Protective Service (e.g., Fire Fighting, Police Officer, Correctional Officer)</option>
      <option value="49">-  Chef or Head Cook</option>
      <option value="50">-  Cook or Food Preparation Worker</option>
      <option value="51">-  Food and Beverage Serving Worker (e.g., Bartender, Waiter, Waitress)</option>
      <option value="52">-  Building and Grounds Cleaning and Maintenance</option>
      <option value="53">-  Personal Care and Service (e.g., Hairdresser, Flight Attendant, Concierge)</option>
      <option value="54">-  Sales Supervisor, Retail Sales</option>
      <option value="55">-  Retail Sales Worker</option>
      <option value="56">-  Insurance Sales Agent</option>
      <option value="57">-  Sales Representative</option>
      <option value="58">-  Real Estate Sales Agent</option>
      <option value="59">-  Other Services Occupation</option>
    </optgroup>
    <optgroup label="Agriculture, Maintenance, Repair, and Skilled Crafts Occupations:">
      <option value="60">-  Construction and Extraction (e.g., Construction Laborer, Electrician)</option>
      <option value="61">-  Farming, Fishing, and Forestry</option>
      <option value="62">-  Installation, Maintenance, and Repair</option>
      <option value="63">-  Production Occupations</option>
      <option value="64">-  Other Agriculture, Maintenance, Repair, and Skilled Crafts Occupation</option>
    </optgroup>
    <optgroup label="Transportation Occupations:">
      <option value="65">-  Aircraft Pilot or Flight Engineer</option>
      <option value="66">-  Motor Vehicle Operator (e.g., Ambulance, Bus, Taxi, or Truck Driver)</option>
      <option value="67">-  Other Transportation Occupation</option>
    </optgroup>
    <optgroup label="Other Occupations:">
      <option value="68">-  Military</option>
      <option value="69">-  Homemaker</option>
      <option value="70">-  Other Occupation</option>
      <option value="71">-  Don't Know</option>
      <option value="72">-  Not Applicable</option>
    </optgroup>
  </select>
</fieldset>