Which relation is a function?
O A. {(-5, 4), (3, -2), (-2, 0), (8, -2)}
B. {(4, 6), (-1, -3), (4, -2), (3,5)}
C. {(6, 1), (3, 4), (5, 3), (6, 2)}
D. {(-4,-4), (2, -4), (7,3), (7, -1)}