Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Question: Does perineal body stretch during labor predict perineal laceration , postpartum incontinence , or postpartum sexual function : a cohort study?
Answer: PB stretch during labor is unrelated to perineal laceration, postpartum incontinence, sexual activity, or sexual function.
no