Final answer:
The underlined pronoun 'he' in the sentence is a predicate nominative.
Step-by-step explanation:
The underlined pronoun in the sentence, 'Both Ben and he will graduate at the same time,' is used as a predicate nominative. In this sentence, 'he' renames the subject 'Ben' and is used to identify or rename the subject. It is functioning as a predicate nominative because it is following a linking verb, 'will.'
Learn more about Identifying the role of pronouns in a sentence