Harriet Tubman's maintained?

[amysky_0205]

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

OA: D

don't know where to start with...
can someone explain this in details? thank u so much,

[The Iceman]

The starting point should be understanding the intended meaning of the sentence. This is true for any SC question you solve.

Post the civil war 'contemporaries of Harriet' maintained an opinion about what qualities Harriet Tubman had during the war times.

As soon as we understand this, we know that there are two past events at play and that the bearing of one action is on the other. This warrants the use of past perfect to express the earlier event and simple past for the later past event.

Eliminate A,C, and E.

A is wrong because "contemporaries of" should take the noun subject Harriet Tubman and not its possessive form. B and C also have this mistake.

D wins