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.
Q: Question: Is leg extension power a pre-disaster modifiable risk factor for post-traumatic stress disorder among survivors of the Great East Japan Earthquake : a retrospective cohort study?
Answer: Leg extension power is a potentially modifiable pre-disaster risk factor among men for attenuating the severity of PTSD symptoms associated with great disasters such as the Great East Japan Earthquake among men.
A:
yes