Which of the following relations represents a function?

Question 4 options:

{(–1, –1), (0, 0), (2, 2), (5, 5)}


{(0, 3), (0, –3), (–3, 0), (3, 0)}


{(–2, 4), (–1, 0), (–2, 0), (2, 6)}


None of these