Answer:
a. "Impressionism" is a term that applies primarily to an art movement of the late nineteenth century, but the music of some composers of the era is also considered impressionist.
Explanation:
Parallel structure is the repeated usage of a given grammatical word, most times in a way that makes a parallel construction, thereby distorting the meaning.
Therefore, the sentence with the LEAŞT parallel in structure and therefore, the
least effective stylistically is option A.