Answer:
The first table in the image represents a function.
Step-by-step explanation:
This was a little of a given at first sight, let me explain.
The first table has 4 different inputs (x). All the other 3 tables have 2 same inputs (x) with different outputs (y).
It is a rule in functions that a function cannot have 2 different outputs from 1 input. So, we know that the first table represents a true function.