Find the derivative of the function y = x^3 + (6 - x)^3 using the Generalized Power Rule. Which of the following options correctly represents the derivative?

A) 3x^2 + 3(6 - x)^2
B) 3x^2 - 3(6 - x)^2
C) 3x^2 + 3(6 - x)
D) 3x^2 - 3(6 - x)