Answer:
f(x) = 7 is an even function.
Explanation:
Any function is even when
and gives a graph that is symmetric with respect to the y-axis.
We are given these options and we have to check whether which of them is an even function:

and
- This function is not even

and
- This function is not even

and
- This function is not even

and
- EVEN FUNCTION
We get the same value for
and
, therefore f(x) = 7 is an even function.