Which of the following lists of ordered pairs is a function?
OA. (2, 4), (3, 9), (4, 16), (5,25)
OB. (2, 4), (-2, 4), (3,9), (-2,-4)
OC. (1, 1), (2, 3), (1, 5), (4,7)
OD. (0, 2), (4, 2), (0, -4), (4, -2)