Answer:
A, C, E, F
Explanation:
Functions mean that each x-value can only go to one y-value, but the same x-value can't go to 2 different y-values.
Different x-values, such as x=-4 or x=5, CAN go to the same y-value as shown in C.
But for B, x=5 can't go to both y=0 and y=8