A1) Since Employee and volunteer objects extends StaffMember,
then StaffMember is their super class,so they internally get auto casted
to their super type upon initializing a field of type StaffMember.
However both Executive and Hourly extends Employee so their main super parent
of it also is  StaffMember,so we to conclude that Fields of type StaffMember
can be initialized with its sub types Volunteer and Employee :: Executive , Hourly.