Firstly, set g(x) to zero:

So for this, we will be factoring this function using the difference of squares. The difference of squares is
. Using our function, apply this as such:

Next, we are going to apply the Zero Product Property, which states that "if a × b = 0, then either a or b = 0 or both a and b = 0." In this case, a = x + 5 and b = x - 5. Solve each for zero:

The zeros of this function are 5 and -5. The correct option is C.