The sentence that uses parallel structures is B) My three favorite activities are writing, reading, and going to the library.
A parallel structure means that the same form of a verb is used in a sentence, and as you can see, here only gerunds are used - writing, reading, going - they all have -ing in the end.
The other sentences don't have a parallel structure because they don't use the same forms.
This extract if from 'The Leap' by Louise Erdrich.
Explanation:
It is about a blind mother who is surviving about half of the blindfold trapeze act, the Flying Avalons. The daughter says how she was saved by her mother thrice.
First she was saved when a tent pole cracked and fell on the town square. The father and mother gave her life. the other incident was when their house caught fire, her mother saved her.
The girl trusted her mother and was saved.
