Concept:The clause after the semicolon must be a complete sentence with both a subject and a verb.Explanation:The intended meaning is: Remember to return it to Ruth; it is hers.Here, "it" is the subject and "is" is the verb.The contraction "it's" correctly combines "it is.""Its" shows possession, "it" has no verb, and "is" has no subject.Answer:B. it's