请教--老PREP 15题

10gmat

15. Even though sub-Saharan Africa often evokes images of drought and famine, researchers say that the area is the home of more than 2,000 grains, vegetables, roots, fruits, and other foods that have the possibility for feeding the continent, even other parts of the world.

(A) have the possibility for feeding the continent, even

(B) have the possibility of feeding the continent, even of

(C) could feed the continent, so even with

(D) could feed the continent and even

(E) could possibly feed the continent and, in addition, for even

答案是D，没有异议，但是为什么这里用could啊？句子的整个时态都是一般现在时啊？

crazyxxx

could这里表示可能,和时态无关,可以用以一些委婉的表达.
could you please.....时态是?

10gmat

那为什么不用can呢