问题详情

Why is Regan called the intellectual leader of the animal rights movement？

A．He is a philosopher in the field of animal rights protection.

B．He helps to make animal rights movement an academic subject.

C．He has written many books on how to protect animal rights.

D．He proves that animal societies have their moral standards as human societies do.

请帮忙给出正确答案和分析，谢谢！