Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
One example is below.
Q: Question: What's the difference between the following examples: Neither of my teachers are mathematicians. None of my teachers are mathematicians.
Answer: Neither - not either - implies that there is a choice of only two. So 'neither of my teachers' is only correct if there are exactly two teachers, 'none of my teachers' can be any number.
A: yes
Rationale: The answer is well in context with the question and gives a proper explanation to resolve it. Hence, the output "yes" is correct.
Q: Question: Is singular correct, or is plural of "credential" correct for a single username & password pair?
Answer: This isn't a question you can answer by thinking about the grammar - it's just a case of conventional usage. I've previously worked in the tech industry, and we would always say credentials, never credential. That would still be true even if the credentials were a single item like a certificate. [Edit to add: but Samuel has provided a counter-example to this in a comment on the OP.] In wider English, credential is valid - it's used for example in this Wikipedia article - but it's still more common to use the plural (see Oxford Dictionaries for confirmation). For example, I could say that I have presented my credentials to someone if I have shown them my passport, even though I've only shown them one physical item.
A:
yes