Answer:
A. is the answer
Explanation:
y as a function of x meaning:
Every x has a y, but the x value cannot repeat and every x has it's own y.
Example:
x: 1 2 3 4 5
y: 2 4 6 8 10
This is y as a function of x because the x values do not repeat and they each have a y value.
Example 2:
x:3 4 5 3 6
y: 1 2 3 4 5
This wrong because the 3 in the x value repeats twice which cause y not to be a function of x.
The reason why it wouldn't be B is because of -1
The reason why it wouldn't be C is because the y values repeat
The reason why it wouldn't be D is because all the x values are -7
Hope this helped!