Which of the following relations describes a function?
OA. {(-3,0), (0,3), (3, 0), (0, -3))
OB. ((-4,4), (-3,-3), (-3, 3), (0, 0)}
OC. {(0, 0), (3,-3), (3, 3), (4,4)}
OD. {(-4,4), (-3, 3), (3, 3), (4,4)}