Which relation is a function? Select all that apply.

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

{(3,1), (−3,1), (4, 3), (−4,3)}

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

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

{(3,3), (−2,−2), (0, 0), (−4,4)}