Instructions: 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.
Input: Question: Are maternal serum levels of macrophage colony-stimulating factor associated with adverse pregnancy outcome?
Answer: This study suggests that absolute levels and relative changes in maternal serum M-CSF levels during pregnancy are associated with adverse pregnancy outcomes.
Output:
yes