Children's understanding of sarcasm occurs only when a mocking or overly enthusiastic tone of voice is present. does not differ from adults' understanding of sarcasm. is well developed by the time children enter school. occurs only when a comment does not match the context of the comment.

The answer in the given choices above is -- is well developed by the time children enter the school. It is because children and adults have different views of sarcasm and the child will only know about it once he or she is interacted with other children in which he or she will likely be in a school setting.

Currently, as of february 2016, an american traveling in france would be by the exchange rate. the weakness of the euro and the strength of the us dollar means that items in france cost less to an american than they otherwise would. of course, if this trend reverses and the us dollar weakens and the euro strengthens, such as was happening in early 2008, an american traveling in france would have an adverse experience because items would cost relatively more.