The question of whether to divest themselves of stock in companies tha

(A) than
(B) than those of
(C) than is so of
(D) compared to
(E) compared to those of

Answer "B"

When you perform comparisons you need to make sure that the left side is correctly compared to right side. Let's dissect the question stem...
The question of whether to divest themselves of stock in companies that do business in South Africa is particularly troublesome for the nation’s 116 private Black colleges because their economic bases are often more fragile than most predominantly White colleges.

A comparison is being performed between the "economic bases" of the nation's 116 private Black colleges and Predominant white colleges. Is the comparison correct? NO, how can you compare the economic bases with Predominant white colleges, however, you can compare the economic bases of the nation's 116 private black colleges with those of the Predominant white colleges.


Compared To Vs Compared With:
Compared to is used to compare two dissimilar things
Compared with is used to show the similarities or dissimilarities between two things. Should we not be using Compared with here since we actually mean to compare the economic basis between the two college communities.