I was very busy that day. Otherwise I _________in the discussion．

A．would take party

B．had taken part

C．took part

D．would have taken part

哪种病变可选择性损害神经轴索或髓鞘，而未受损部分则可保持完整（）

A.结缔组织病变

B.自身免疫性周围神经病

C.中毒性和营养缺乏性病变

D.遗传代谢性疾病

E.感染性疾病