Identify the choice that best describes the underlined word in the sentence.

part of a compound subject

The underlined word "violin" is part of a compound direct object.

To identify the choice that best describes the underlined word in the sentence "With practice, both Kendra and Jason mastered the violin," we need to analyze the sentence structure.

In this sentence, the underlined word is 'violin.' To determine its role in the sentence, we need to look at the function it serves.

The subject of the sentence is 'both Kendra and Jason,' which means 'violin' cannot be part of a compound subject.

The predicate of the sentence is 'mastered,' which refers to what the subject (Kendra and Jason) did. 'Violin' does not play a role in the predicate, so it is not part of a compound predicate.

Therefore, 'violin' in the sentence is not part of a compound subject or a compound predicate.

The correct choice is: a direct object.