y is not a function of x since the x value do not correspond to exactly one y value (option C)
Step-by-step explanation:
For y to be a function x, the x values must have only one y values.
Looking at the mapping:
-3 (x value) has two y values (-1 and 3)
-7 (x value) has two y values (3, 5)
Hence, y is not a function of x since the x value do not correspond to exactly one y value (option C)