The sentence which uses parallelism effectively is, 'The large plant-eating dinosaurs were quite slow, rather stupid, and extremely hungry.'
Answer: Option C.
Explanation:
When two or more phrases or clauses in any sentence have similar grammatical structure, that is when parallel structures are formed. Parallelism is simply the similar construction of any sentence.
For example, the line ‘The large plant-eating dinosaurs were quite slow, rather stupid, and extremely hungry’ is a parallel structure. We can see that the sentence is written in an effective way. The words ‘slow’, ‘stupid’, and ‘hungry’ are adjectives which describes the dinosaurs, thus creating a balance.
The other mentioned examples on the other hand doesn’t use parallelism effectively.