Hey! This is gonna be easier than you think. So basically, X is the amount of seconds, and Y is the number of meters. What determines if something is a function, is if each X has exactly one Y corresponding to it. You cannot have the two of the same number that are X. For this question, the answer would be A. Because each ~input~ has one ~output~. If this doesn’t make sense, tell me and I’ll try to explain it better :)