Which of the following relations is not a function?
A
(6, 4), (-3, 2), (3, 1), (-6, 2)
B
(-6, 4), (3, 3), (-3, 1), (6, 2)
C
(-3, 4), (3, 2), (6, 1), (-6, 5)
D
(3, 4), (-3, 2), (3, 1), (-6, 2)
A
B
C
D