Which word group best completes the sentence without introducing an inappropriate shift in tense? after the storm blew the pecans to the ground, a. we have raced the squirrels to gather the windfall. b. we had been racing the squirrels to gather the windfall. c. we will be racing the squirrels to gather the windfall. d. we raced the squirrels to gather the windfall.

The correct answer is D, because that is the only appropriate shift in tense. A isn't correct because present perfect tense (have raced) is used inappropriately, when it should have been past perfect. B is also incorrect because past perfect means that that action happened before the storm blew, which is not the case. C features future continuous tense, which is impossible due to shift in tense. Therefore, the answer is D, because there is an appropriate tense in that sentence, past simple. 

Explanation:

1 a 2 b 3 c 5 a