Which of the Following Is Normally a Lawful Question to Ask

Which of the following is normally a lawful question to ask DURING an employment interview (not as verification submitted after employment) ?

A) "Which years did you serve in Vietnam, and what type of discharge did you get?"
B) "If the company pays for additional schooling, what courses would you like to take?"
C) "How did your parents come to this country?"
D) "What is your date of birth?"