Which sentence demonstrates parallel structure in a list?

• A. She enjoys reading, writing and painting.
• B. She enjoys reading, writing, and painting.
• C. She enjoys reading, to write, and painting.
• D. She enjoys reading, writing and paint.

Answer: (B)

Parallel structure means the items in a list should be presented in the same grammatical form. In this sentence, all three activities are expressed as gerunds: reading, writing, painting. That uniform form keeps the list balanced, clear, and easy to read. The version uses a serial (Oxford) comma before the final “and,” which helps clearly separate each item and reinforces the even, parallel feel of the list.

If you switch to an infinitive like “to write” or to a non -ing form like “paint,” the items no longer share the same structure, which breaks the parallel pattern. The sentence without the serial comma can still be acceptable in some styles but is less clearly parallel or may invite ambiguity, whereas the version with the comma makes the parallel structure unmistakable.