Which relation is a function?
A. (1, 0), (3.0), (1.1), (3, 1) (1.3)
B. (1, 1), (2, 2), (3, 3), (4, 4). (5, 8). C. ( 2, 7), (6,5), (4.4), (3, 3), (2, 1)
D. (9. -3), (19, 3) (4, -2), (4, 2), (0, 0)