Final answer:
The parallel sentence is Option C: 'Tell me where you were, what you were doing, and why you were doing it.' This option uses a similar grammatical structure for each element being asked about, which creates a balanced and clear sentence.
Step-by-step explanation:
The question asks which sentence is parallel. Parallelism in writing means using similar structures in a sentence to create balance and make the ideas clearer and easier to remember. To maintain parallelism, the sentence components that are being listed or compared should follow the same grammatical structure.
Option C is the parallel sentence. It correctly uses parallel structure in the form of three clauses that explain what the speaker wants to know: where the listener was ('where you were'), what the listener was doing ('what you were doing'), and the reason for the listener's actions ('why you were doing it'). Each of these elements follows a similar grammatical pattern, creating a harmonious and rhythmically pleasing sentence.