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.

[EX Q]: Question: If you, for example, have to add a person to an application whilst that person is on the phone, how do you politely ask for that person's gender if the voice and/or name has not proven decisive? To clarify why I posted this question on this site: I was looking for an answer within the context of the English language and usage. The given answers have proven that this question really isn't off-topic, other languages know different distinctions that are relevant to addressing this issue. 
Answer: I would simply ask, "Which box should I check?, M or F?, and keep in mind, this phone call is monitored"...a barely audible snicker should convey 'politeness', followed by , "seriously, we have a pool going on and I need to get this one right!".
[EX A]: no

[EX Q]: Question: Could you tell me some suitable idioms to express this situation: A guy told you a joke, but it's not funny at all. In Japanese, we say "He slipped" or "His joke was so cold that the air got frozen," for that situation. Are there any similar phrases in English? 
Answer: A common expression for this is to fall flat (from the "idioms" section of thefreedictionary.com): fall flat if an entertainment or a joke falls flat, people do not enjoy it and do not think it is funny Several attempts at humour during his speech fell flat. if an attempt to influence people's behaviour or opinions falls flat, it fails The advertising campaign which had worked so well in the US fell flat in China. The statement that pregnancy is not an illness falls flat with many morning sickness sufferers. The first meaning is the one you're after, so you could say: I told a joke but it fell flat.
[EX A]: yes

[EX Q]: Question: Does "egoistic" and "egotistic" mean the same thing? 
Answer: An "egotist" thinks that the world revolves around him/her. An "egoist" is a petty soul, disregarding of the rights and needs of others. It is synonymous with "selfish person".
[EX A]:
no