Answer:
whom*
Step-by-step explanation:
Whom is an objective pronoun that is used for formal English. It is used as the object of a verb or preposition. Whom should replace the object of the sentence. Consider who is having something done to them when finding the object of the sentence. The object is the person, place, or thing that something is being done to.
Who is used to provide more information about a person or people mentioned previously in a sentence. It is also a subjective pronoun. A subjective pronoun is a pronoun (I, me, he, she, etc.) that is used as the subject of the sentence. Who replaces the subject of the sentence.
Are you referring to someone who is doing something (who), or are you referring to someone who is having something done to them (whom)?