Sentence Correction (SC) | QOTD: A 1972 agreement between Canada and the United States

A tough call between A and D. I fell for A , but here is why I feel D should be the answer :

The point of contention is whether or not past perfect tense is justified in this case. It is not - because the two actions talked about : reduced and allowed are not in sequence here. Municipalities are still being allowed to draw after a reduced amount that was set in 1972. The sequencing is corrected by removing past perfect form. Hence option D.

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