Follow the steps for graphing a rational function to graph the function $G(x)=\frac{4 x}{x^{2}-64}$. If needed, first write the given function as a single rational expression. Then factor the numerator and denominator of $G(x)$. Select the if necessary, fill in the answer box to complete your choice. A. $G(x)=\square$ (Type your answer in factored form. Do not simplify.) B. $G(x)$ cannot be factored further.

Step 1 ：The given function is $G(x)=\frac{4 x}{x^{2}-64}$.

Step 2 ：First, we factor the numerator and denominator of the function $G(x)$.

Step 3 ：The numerator is already in its simplest form, which is $4x$.

Step 4 ：The denominator can be factored as a difference of squares. The difference of squares formula is $a^2 - b^2 = (a - b)(a + b)$.

Step 5 ：In this case, $a = x$ and $b = 8$. So, $x^2 - 64 = (x - 8)(x + 8)$.

Step 6 ：Therefore, the factored form of $G(x)$ is $\frac{4x}{(x - 8)(x + 8)}$.

Step 7 ：\(\boxed{G(x)=\frac{4x}{(x - 8)(x + 8)}}\) is the final answer.