Answer:
The very last set
{(0, 2), (1, 4), (2, 6), (3, 6)}.
The reason why is because of the vertical line test. If there are two y-coordinates on a x-coordinate then it is not a function. A function is that each x-coordinate has a y-coordinate with the x-coordinates being different.
Example is above. If you have any questions then leave a comment. Good luck!
Step-by-step explanation: