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.

[EX Q]: Question: Is tumor differentiation a risk factor for lymph node metastasis in elderly patients with early gastric cancer?
Answer: Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.
[EX A]: no

[EX Q]: Question: Does cheating explain selective differences at high and low relatedness in a social amoeba?
Answer: These results suggest that social competition and something beyond solitary growth differences occurs during the vegetative stage when amoebae eat bacteria and divide by binary fission. The high degree of repeatability of our results indicates that these effects are strong and points to the importance of new approaches to studying interactions in D. discoideum.
[EX A]: no

[EX Q]: Question: Are s100A8 , S100A9 , and the S100A8/A9 complex in circulating blood associated with prostate cancer risk-A re-evaluation study?
Answer: Our re-evaluation study showed that S100A8, S100A9, and the complex S100A8/A9 were less indicative than %fPSA and that they are not suitable to replace PSA.
[EX A]:
no