请教一语法点

v22

202. After the Civil War, contemporaries of Harriet

Tubman's maintained that she has all of the qualities of a great leader: coolness in the face of danger, an excellent sense of strategy, and an ability to plan in minute detail.

(A)  Tubman's maintained that she has

(B)   Tubman's maintain that she had

(C)  Tubman's have maintained that she had

(D)  Tubman maintained that she had

(E)   Tubman had maintained that she has

什么时候用sth of sb's？ 记得以前读书的时候，有一个语法点：a friend of mine，而不是a friend of me。。。这题，如果B中的maintain 是现在时态，而是一般过去时，我会选B了。。。。NN们，能帮忙看看？什么时候用sth of sb's，什么时候是sth of sb？

howardwang

在一般的语法中a friend of mine指我的朋友中的一个（强调我的朋友中的一个，而不是我的一个朋友），但是，在gmat中sth of sb's一般认为是不正确的。og中有过解释。