D) Len's favorite pastimes are listening to music, going to baseball games, and hanging out with his friends.
Explanation:
Parallel structure/parallelism in writing is the use of words in a way that is not repetitive and uses the same grammatical pattern to make the sentence easy to understand without ambiguity.
Therefore, the sentence that correctly uses parallelism is option D.
Answer: Teachers are better at handling time while doctors are not time specific. They always arrive late. Teachers treat more people at one time than doctors.