Noun
English Wikipedia has an article on:interrogative pronounWikipedia
interrogative pronoun (plural interrogative pronouns)
(grammar) A pronoun used in a question. In English, the five interrogative pronouns are what, which, who, whom, and whose (also used as relative pronouns). These require no antecedent.
What did you say?
Who said that?
To whom was that said?
Which student said that?
Whose question was that?