What prevents the man from taking the poets of 1960s class?A.Its only open to poetry majo

What prevents the man from taking the poets of 1960s class？

A．It"s only open to poetry majors.

B．It requires another class first.

C．It"s already full.

D．He wants to have a rest.

请帮忙给出正确答案和分析，谢谢！