The correct answer is option C. As Elliot climbed the temple steps, he could see the marketplace stretching out before him: merchants hawked goods, families browsed stalls, and teenagers spread gossip.
The sentence that maintains a parallel structure throughout is:
C. As Elliot climbed the temple steps, he could see the marketplace stretching out before him: merchants hawked goods, families browsed stalls, and teenagers spread gossip.
This sentence employs parallel structure by consistently using the same grammatical form for each element in the series. In this case, the parallel structure involves the use of simple verb phrases ("hawked goods," "browsed stalls," "spread gossip") for all three components of the list, creating a balanced and grammatically parallel structure.
Options A and B lack consistency in structure. Option A changes from simple verb phrases to verb phrases with linking verbs ("families were browsing stalls"), disrupting the parallelism.