I would’ve probably needed help on this too, a very strange way to ask, but the same rules apply as they would to a regular graph.
In order to have a function, we need every value of the domain (the names) to have only one value from the range (emoticons).
A simple answer to this would be to apply each name with the emoticon it is already applied to (but many solutions are possible), {(A, ), (B, ), (C, ), (D, ), (E, )}
This is a pretty confusingly worded question that I’m pretty sure is just testing your understanding of a function and it’s relation between domain and range. I hope this helps, and I can certainly provide a more in depth explanation of the relationship if you need.