Which of the following is an example of a relative pronoun?

The answer "who" is considered a relative pronoun because it is used to introduce a relative clause, which provides additional information about a noun. For instance, in the sentence "The teacher who inspires me is retiring," the word "who" connects the clause "who inspires me" to the noun "teacher," describing which teacher is being talked about.

Relative pronouns are crucial in sentences because they help to connect clauses and identify or give more detail about the noun in question. This is different from other types of pronouns, such as personal pronouns ("you," "him") that simply replace nouns in a sentence, or possessive pronouns like "yours," which indicate ownership. Thus, "who" effectively shows its function in relative clauses, establishing it as the correct choice in this context.