[求助]大全271

1.        Eaten in the Mediterranean countries, northern Europeans viewed the tomato with suspicion, for they assumed it had poisonous properties because of its relationship to deadly nightshade.

(A) northern Europeans viewed the tomato with suspicion, for they

(B) northern Europeans were suspicious of the tomato, and they

(C) the tomato was viewed with suspicion by northern Europeans, who

(D) the tomato was suspicious to northern Europeans, and it was（C）

(E) the tomato was viewed with suspicion by northern Europeans, it being

这里C的who assune it had...是assume的什么用法，是不是assume that?但宾语从句中的that不是不能省略吗？

谢谢！