请教neither and nor 的区别？多谢

看到这样一道题：（新东方语法补充材料460题)
Unlike the Shlites, who constitute the other major branch of Islam, the Sunnites do not await the Mahdi as a messenger from God, (nor do they endow him) with divine qualities or immunity from failure in judgment.
A) nor do they endow him
B) but they do not endow him
C) neither do they endow him
D) and they neither endow him
E) while endowing him neither

答案选A,可是为什么C不可以

ETS倾向于将neither单独理解为：既不或两者都不

将nor单独理解为：也不

也即为什么A而不是C