19. It is widely assumed that a museum is helped financially when a generous patron donates a potential exhibit. In truth, however, donated objects require storage space, which is not free, and routine conservation, which is rather expensive. Therefore, such gifts exacerbate rather than lighten the demands made on a museum’s financial resources.

Which of the following, if true, most seriously weakens the argument above?

(A) To keep patrons well disposed, a museum will find it advisable to put at least some donated objects on exhibit rather than merely in storage.

(B) The people who are most likely to donate valuable objects to a museum are also the people who are most likely to make cash gifts to it.

(C) A museum cannot save money by resorting to cheap storage under less than adequate conditions, because so doing would drive up the cost of conservation.

(D) Patrons expect a museum to keep donated objects in its possession rather than to raise cash by selling them.

(E) Objects donated by a patron to a museum are often of such importance that the museum would be obliged to add them to its collection through purchase if necessary.

我觉得答案是B，可是给的是E。 我认为如果是E的话，museum且不是更要付出钱，从而加重负担。那样的话，怎么能说weaken呢

哪位高人指点一下，先谢谢了