Answer:
The sentence that uses parallel construction correctly is:
C. My plans for this summer include working out daily, watching movies, and going to the lake.
Step-by-step explanation:
For a structure to present a parallel construction, it has to repeat a certain grammatical form inside the sentence. Parallelism helps make the sentence easier to understand and more consistent. Let's take a look at each sentence:
A. On vacation I will spend time reading, visiting museums, and go to my aunt's house. - Parallelism should start after the word "time", since everything that comes after it is supposed to indicate what the speaker will spend time doing. The first two items are okay, using an "ing" form. The last one (go to my...) is different.
B. I always watch the annual fireworks, swimming in the lake, and hike to see the rocky coast. - The second item is different in this case. While the other two use verbs agreeing with the first person singular, "swimming" uses "ing".
C. My plans for this summer include working out daily, watching movies, and going to the lake. - This one is CORRECT. The three items mentioned (working out daily, watching movies, and going to the lake) all use the same structure.
D. My family's plans include travel by train, to visit an amusement park, and a tour of an aquarium. - In this case, each item is different. The first one is a verb without "to". The second one is a verb with "to". The last one does not even present a verb. There is no parallelism at all.