Answer:
Hi, there your answer will be C.
Explanation:
The reason why is because X(Input) can not be repeated the same
for example the coordiante( 1,3) and (1,4). See there are two ones which make them not function
Also, if you're having trouble with Functions and nonfunctions
REMEMBER THS
Function: X and y has to be separarte and can't have the same X
NON-FUNCTION- WHEN X REPEATS ITSELF
Hope this helps :)