Directions: The following question presents a sentence, part of which or all of which is underlined. Beneath the sentence you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.

The auto industry has experienced one of its most significant trends in the last 50 years, which is the migration of motorists from passenger cars to minivans, sport utility vehicles, and pickups.

D is correct because it concisely states that 'one of the most significant trends...is' the migration, using clear subject-verb structure without unnecessary words. A is incorrect because 'which is' after the comma creates a relative clause that makes the sentence wordy and awkward. B is incorrect because 'of the trends...' creates a clumsy opening and 'has been one of the most significant' is unnecessarily wordy. C is incorrect because 'has been experiencing has been' is redundant and awkward. E is incorrect because it is extremely wordy with multiple layers of relative clauses and 'that it has had, that of' making it convoluted.