A pronoun is used to substitute a noun. In order for
it to substitute, it must have a clear antecedent. Personal pronouns are used
to substitute nouns with ownership. There are three persons point of view.1st
person is when the subject is the one who is speaking (e.g. I, me, my, mine, we, us, our, ours).
2nd person is when the subject is the one being spoken to (you, your, yours). 3rd
person is when the subject is the one spoken about (he, him, his, she, her, hers, it, its, they, their, theirs).
The answer is C. their. You use it when it's plural
