Answer:
Third set.
(-2, 2), (0, 2), (7, 2), (11, 2)
Explanation:
A function is defined as a relation where each x-value (domain), has only one y-vale assigned (range). If one x-value has more than one image in the range, therefore, that's not a function. So, let's see which relation represents a function.
First: (0, 0), (2, 3), (2, 5), (6, 6).
As you can see, this set doesn't represent a function, because for x=2 there are two images assigned y=3 and y=5.
Second: (3, 5), (8, 4), (10, 11), (10, 6).
Similarly, this relation is not a function, because x=10 has to images, y=11 and y=6.
Third: (-2, 2), (0, 2), (7, 2), (11, 2)
As you can see, this is a function, because each pair has different value in the domain. Notice that there's the same image for each x-value, that still fulfil the definition of a function, because one element in the image can have multiple elements in the domain, what cannot happen is the opposite case.
Fourth: (13, 2), (13, 3), (13, 4), (13, 5).
This relation is not a function, because the same x-value has multiple images.
Therefore, the right answer is the third set.