Identify the elements present in the following sentence $($check all that apply$)$: President Abraham Lincoln, a prolific writer, was deeply troubled by the Civil War.

Identify the elements present in the following sentence $($check all that apply$)$: President Abraham Lincoln, a prolific writer, was deeply troubled by the Civil War.

a passive$-$voice verb

a proper name

an adverb

an appositive phrase

a pronoun