Answer:
option A
option C
option D
Explanation:
A function is a special relationship where each input has a unique output.
There could not be different y values for same value of x but it may have two x-values assigned to the same y-value.
So by following this definition:
In option B
for x = 6
have two different outputs y = -6 and y = -1 REJECTED
In option E
for x = 0
have two different outputs y = 0.5 and y = 2 REJECTED