请教一个题目？

lijiaxuan810823

35.   Federal authorities involved in the investigation have found the local witnesses are difficult to locate, reticent, and are suspicious of strangers.

(A) the local witnesses are difficult to locate, reticent, and are

(B) local witnesses to be difficult to locate, reticent, and are

(C) that local witnesses are difficult to locate, reticent, and

(D) local witnesses are difficult to locate and reticent, and they are

(E) that local witnesses are difficult to locate and reticent, and they are

答案是c，我选的e，觉得difficult to suspicious别扭。

maggiecookies

是这样平行:

are difficult to locate, (are )reticent, and (are) suspicious of strangers

lijiaxuan810823

thanks a lot！