In talking to a mixed class of students, a teacher says, "When someone knows the answer, I would like him to raise his hand." In the past, this was the grammatically correct way to phrase it, but it is not consider proper today. Which of the following ways of saying the same thing is now considered appropriate?

I. Anyone who knows the answer should raise his hand.
II. When someone knows the answer, I would like them to raise their hand.
III. Anyone who knows the answer should raise his or her hand.
IV. I would like to see a raised hand from anyone who knows the answer.

A. I and II
B. III only
C. II and III
D. III and IV
E. All of the choices are correct