*E. They were strolling downtown when they had heard the crash. *
Another possible answer is B. Though the weather had been rough, we made it home safely.
The sentences 'By the time I returned home three hours had passed' and 'Though the weather had been rough, we made it home safely' correctly use shifts in verb tense . The other sentences contain incorrect shifts in tense. ;
The sentences with acceptable shifts in verb tense are A, B, and D. These sentences maintain a logical timeline regarding the actions they describe. Sentences C and E present incorrect shifts that confuse the timeframe of actions.
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