Correct Answer: D
Explanation:
This sentence has a problem with verb tense. Since the first part of the sentence, "After the canoe flipped over and the provisions were lost," uses two past-tense verbs ("flipped" and "were"), the rest of the sentence needs to be in past tense too, since it is describing events that took place at the same time as those described earlier in the sentence. "Are declaring" is in the present progressive tense, so it contains the sentence's error. You could correct the sentence by changing "are declaring" to "declared," yielding the sentence, "After the canoe flipped over and the provisions were lost, the campers declared the trip a disaster."