我也选错D了,现在看来,如果是D,句子应该是:
increases (主语)in the sales of the 50 drugs (修饰主语的)that were advertised most heavily(修饰drugs的), accounting for almost half of the $20.8 billion increase in drug spending last year, while the remainder of the increase came
导致这个句子只有一个increases主语,之后什么都没了。