Which of the following sets of ordered pairs represent a function? Select two that apply.
A.
(5,9), (2, 5), (8, 4), (6, 1), (4,3), (7, 8), (3, 7), (1, 2)
B.
(10,4), (14,3), (12, 8), (4, 1), (14, 8), (8, 7), (6,5), (8,4)
C
(6,9), (16, 15), (10, 15), (8, 13), (12, 2), (2, 6), (14,9), (4,3)
D
(6, 15), (2, 12), (1, 2), (4, 10), (5,9), (3,5), (3, 18), (5, 4)