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: Does stopcock lumen contamination reflect the full burden of bacterial intravenous tubing contamination : analysis using a novel injection port?
Answer: Effluent culture is a more sensitive marker of IV fluid system contamination than injection port lumen culture. A novel protective device on the stopcock (Port Guide) significantly reduced IV fluid system bacterial contamination.
[EX A]: no

[EX Q]: Question: Does single copy of variant CYP2A6 alleles confer susceptibility to liver dysfunction in patients treated with coumarin?
Answer: No evidence was obtained that the studied polymorphism in CYP2A6 is a determinant of the coumarin-associated liver dysfunction.
[EX A]: no

[EX Q]: Question: Does determinants of life expectancy in medullary thyroid cancer : age matter?
Answer: In MTC patients, extrathyroidal extension and stage at diagnosis are the only independent predictors of (recurrence-free) life expectancy. Patients diagnosed in an early stage of disease and patients without detectable recurrence have favourable life expectancy independently of biochemical cure.
[EX A]:
no