Determine If the Following Is a Function or Not $\in \{ 0,2,4,6 , \ldots \}$

Multiple Choice

Determine if the following is a function or not.
-f(x) =1 for x $\in \{ 0,2,4,6 , \ldots \}$ and f(x) =0 for $x \in \{ 1,3,5,7 , \ldots \}$

A) Yes
B) No