What is required for the graphic to represent a function?
The same value of x cannot have more than one value of y.
In this question:
We have one value of x with two values of y.
This is at x = 1, which has y = 1 and y = 3.
So one of the ordered pairs (1,1) or (1,3) can be removed to create a set of ordered pairs that represents a function.
Answer:
(1,1) or (1,3)