Answer:
A. it is a function because each input value has exactly one output.
Step-by-step explanation:
A relation is considered to be a function when each domain value (input), X, of the function has exactly one range value (output), Y, that is related to it. This means a domain value, X, (input) of a function cannot have two different range values (output) that are related to it.
However, two or more different domain values (input) can give the same range value (output).
The table of values given shows different input values, of which each has exactly one output value. However, the different input values give the same output.
Therefore, "it is a function because each input value has exactly one output".
