Which ordered pairs cause this relation NOT to be a function? Why?

Question

{(0, 0.5), (0.5, 1), (3, 1), (1, 6), (3, 2)}
Responses
A (0.5, 1) and (0, 0.5); A function cannot contain decimals.(0.5, 1) and (0, 0.5); A function cannot contain decimals.
B (0.5, 1), (3, 1); The same y-value has different x-values.(0.5, 1), (3, 1); The same y-value has different x-values.
C (3, 1) and (3, 2); The same x-value has different y-values.(3, 1) and (3, 2); The same x-value has different y-values.
D (3, 1) and (3, 2); The x-value in a function cannot be greater than the y-value.(3, 1) and (3, 2); The x-value in a function cannot be greater than the y-value.

Answer 1

A relation is not a function if any x-value corresponds to more than one y-value. In the set of ordered pairs given, we see that the pair (3, 1) and (3, 2) both have the same x-value of 3 but different y-values.

Thus, the correct response is:

C (3, 1) and (3, 2); The same x-value has different y-values.

This means that the relation is not a function because the x-value of 3 is associated with two different y-values.