Answer :
Functions can only have 1 value of 'x'.
So the correct answer is A.
x-values in Option A:
-4, -2, -1, 2, 3
None of these are the same, therefore this is a function.
So the correct answer is A.
x-values in Option A:
-4, -2, -1, 2, 3
None of these are the same, therefore this is a function.