Which relation is not a function?
A. x 147
21 28 35
y 7
14 7
35 21
B. {(8,4), (4,8), (12, 4), (16, 20),
(20, 12)
O C. (9,3), (5, 16), (6, 8), (9, 10),
(11,13), (1,7)
D.
