Question

Which relation is not a function?

A (7, 3), (7, 6), (7, 9), (7, 12),(7, 15)
B (−4, 6), (0, 6), (7, 6), (4, 6),(−7, 6)
C (4, 1), (8, 2), (12, 3), (16, 4),(20, 4)
D (1, 3), (3, 5), (5, 7), (7, 9), (9, 1)

Answer 1

The Answer is A.

Repeating number is not a function. It's ok to have repeating number in Y or the range but not the X which is the Domain.