It's true that the old road is less direct and a bit bumpy. We won't take the new one ______ because we feel as safe on it.

A．however

B．though

C．nevertheless

D．whatsoever

哪一型蝶窦对施行经蝶窦垂体肿瘤切除术最为有利（）

A.甲介型

B.鞍上型

C.鞍前型

D.鞍型

E.鞍后型