Find the derivative of the function by using the definition. Then determine the values for which the function is differentiable.
\(y = \frac{5x}{x - 4}\)
\(y' = \)
Choose the correct answer below. Fill in the blank to complete the answer as needed.
A. The function, y, is differentiable for all real numbers except \(x = \)
B. The function, y, is not differentiable.
C. The function, y, is differentiable for all real numbers.