When would you be most likely to use an interrogative pronoun?

to direct attention to a specific person, place, or thing
to add emphasis to a noun or a pronoun
to introduce a question
to introduce an adjective clause

Interrogative pronouns are pronouns that are used when asking questions. These are the only pronouns with no antecedents because it is unknown. You would most likely use an interrogative pronoun when introducing a question. Interrogative pronouns include what, which, who, whom, and whose.