Which of the following lists of ordered pairs is a function?

A. (0, 3), (1, 5), (4, 2), (0, -3)
B. (10, 5), (6, 3), (12, 6), (4, 2)
C. (5, 7), (4, 2), (2, -4), (5, 3)
D. (10, 5), (6, 3), (10, 2), (4, 6)