All we know about the origin of language is that men, unlike animals, ______ invented cert

All we know about the origin of language is that men, unlike animals, ______ invented certain sounds to express thoughts and feelings, actions and things, so that they could communicate with each other.

A．somehow

B．somewhat

C．anyhow

D．anyway

请帮忙给出正确答案和分析，谢谢！