Which word is the indefinite pronoun in this sentence? "I sent out the invitations last week, but many of my friends haven't responded yet," said Carla. A. out B. my C. many D. but

A pronoun substitutes an aforementioned noun.

Definite pronouns: he, she, it, we, you, I, they, me, us, him, her ...

Indefinite pronouns: all, another, any (body/one/thing), every (body/one/thing), none, nobody, some (body/one/thing) ...

The indefinite pronoun here is many.