The Following Sentences Form a Paragraph

The following sentences form a paragraph. Proofread them for inconsistent tense and faulty parallelism. Identify the type of each error in each sentence, or select "correct" if the sentence is free of errors. People held on to pieces of drifting wood or were sitting on top of their houses as they were swept along at a terrifying speed.

A) correct
B) inconsistent tense
C) faulty parallelism