rahul wrote:
A 1972 agreement between Canada and the United States reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes.
(A) reduced the amount of phosphates that municipalities had been allowed to dump
(B) reduced the phosphate amount that municipalities had been dumping
(C) reduces the phosphate amount municipalities have been allowed to dump
(D) reduced the amount of phosphates that municipalities are allowed to dump
(E) reduces the amount of phosphates allowed for dumping by municipalities
(A) reduced the amount of phosphates that municipalities had been allowed to dump
(B) reduced the phosphate amount that municipalities had been dumping
(C) reduces the phosphate amount municipalities have been allowed to dump
(D) reduced the amount of phosphates that municipalities are allowed to dump
(E) reduces the amount of phosphates allowed for dumping by municipalities
First categorization is between reduces and reduced. Clearly, the agreement in past makes "reduces" incorrect.
Of the remaining options A, B and D - Both A and B imply that the agreement is changing something that "Had been" happening.
For Eg -: Saying that - " From Monday onwards, I reduced the number of daily questions I had been solving." ; this statement would mean that I went back in time and reduced the number of daily questions I solved on Sunday and days before that ( which I can't , technically! )
So I'd rather say - "From Monday onwards, I reduced the number of daily questions I solve" ( since i still solve a reduced number of daily questions, unless specified otherwise)..
Hence, D is the right answer!!!