SOMEONE PLEASE HELP ME! I promise i will mark brainlest, but i need the right answer for this. help is much appreciated <3

Answer:
the third choice
Step-by-step explanation:
I haven't done those questions in a long time so I would double check. But I think its choice C because 0 has two functions, and I'm pretty sure that a number can only have 1 output, therefore C is not a function..