Answer:
C
Step-by-step explanation:
If you see the same number used as an x-coordinate more than once, it is not a function.
O{(-4,9), (-9,3), (1,7),(-6, 6)}
O {(-9,5), (3,5), (0,1),(-6,8)}
o {(8,-1),(4,-4),(4, -3), (9,5)} ---> 4 is used twice as an x-coordinate
O{(-2,-2), (-1,0), (0, -5),(-9,-5)}
Answer: C
