Correct Answer: Who

Solution : The correct answer is option 3.

Example:

Because a subject is required in this sentence, the subjective case pronoun "Who" will be used.

A word that is used in the place of a noun is known as a subject pronoun. It functions as the sentence's subject. To identify the action's performer, subject pronouns are typically used in the first part of a sentence, right before the verb.

It serves as a subject in the sentence. To identify the person who is carrying out the action, subject pronouns are typically positioned in the first clause of a sentence, just before the verb.