<form  method="post" id="form">
    <input type="radio" name="calc-ownership" id="calc-ownership-1" value="ooo">
   <label for="calc-ownership-1" class="left-border">ООО</label>
    <input type="radio" name="calc-ownership" id="calc-ownership-2" value="ip">
    <label for="calc-ownership-2" class="right-border">ИП</label>

   <input type="radio" name="calc-activity" id="calc-activity-1" value="service">
   <label for="calc-activity-1" class="col-1">Услуги</label>

   <input type="radio" name="calc-activity" id="calc-activity-2" value="building">
   <label for="calc-activity-2" class="col-2">Строительство</label>

   <input type="radio" name="calc-activity" id="calc-activity-3" value="trade">
   <label for="calc-activity-3" class="col-1">Торговля оптовая и розничная</label>

    <input type="radio" name="calc-activity" id="calc-activity-4" value="restaurant">
   <label for="calc-activity-4" class="col-2">Ресторанный бизнес</label>

   <input type="radio" name="calc-activity" id="calc-activity-5" value="production">
   <label for="calc-activity-5" class="col-1">Производство</label>

   <input type="radio" name="calc-activity" id="calc-activity-6" value="other">
   <label for="calc-activity-6" class="col-2">Прочее</label>

$('.form_calc .btn_wrap .btn').click(function(){
    var path = '/intercompforme2/do.php';
    var formData = $("#form").serialize();
    var success = function( response ){
    if (response.status == "OK") {
        $('#result0').text(response.rate);
    $('#result1').text(response.sber);
    $('#result2').text(response.classic);
    $('input[name=price]').val(response.classic);
    $('input[name=price_sber]').val(response.sber);
    $('input[name=rate-name]').val(response.rate);
    if (response.rate == "ИП УСН") {
        $('.period').text('год');
        $('input[name=period]').val('год');
    }else {
        $('.period').text('месяц');
        $('input[name=period]').val('месяц');
    }
        $('.form_calc .results_wrap, .form_calc .btns_wrap').slideDown();
       }else {
           alert ("Ошибка. Обратитесь к разработчику");
       }
   }
   $.post(path, formData, success, "json");
   return false;
});

$data = $_POST['calc-ownership'] ?? '';

$fp = fopen('log.txt', 'w+');
fwrite($fp, $data);