Which set of ordered pairs represents y as a function of x?

Question 1 options:

{(1, 2), (2, -3), (3, 4), (4, -5)}

{(2, 3), (3, 5), (3, -5), (-2, 8), (-2, -8)

{(1, 2), (2, 3), (3, 4), (3, 5)}

{(1, 3), (1, 5), (1, 7), (1, 9), (1, 11)}