Efforts to equalize the funds available to school districts, a major goal of education reformers and many states in the 1970's, has not significantly reduced the gaps existing between the richest and poorest districts.
(A) has not significantly reduced the gaps existing
(B) has not been significant in reducing the gap that exists
(C) has not made a significant reduction in the gap that exists
(D) have not significantly reduced the gap that exists
(E) have not been significant in a reduction of the gaps existing
The solution given is pretty straightforward that efforts is plural and hence choice D is correct. However, my query is why are we not considering "Efforts to equalize the funds available to school districts" as phrase acting as a subject? Instead of just saying that efforts have blah blah, saying efforts to equalize blah blah has blah blah.
Where am I going wrong? I saw this as a Noun phrase acting as a subject and hence considered it singular.
Second query is, if suppose the subject was indeed singular like say for an example the question had effort (instead of efforts) to blah blah blah, then is there any reason to chose B over C or both would have been correct?