Given the task definition and input, reply with output. 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.

Question: I often hear US citizens say something like this: <Some phrases>. Period. What does period mean when it appears in a sentence by itself in this type of situation? 
Answer: A period is what the full stop is called in American English. Saying period at the end of a sentence is a way of expressing the finality of what is being said. For example, A: But phones are good for taking pictures. B: No, I don't think so. Phones should only be used for communication, period.

yes