Which form of the pronoun correctly completes the sentence Blank mom called and asked you to pick up milk A Yours B Your C You're D Your's?

The 'blank' must be a possessive adjective, a Word that describes a noun (mom) as belonging to someone or something.

The correct pronoun is: B. Your

The Word yours is a possessive pronoun, a Word that takes the place of a noun that belongs to someone or something.

The Word you're is a contraction, a shortened form of the personal pronoun you and the verb are.

The Word your's is not a Word; pronouns indicating possession do not use an apostrophe.