Evaluate. (Be sure to check by differentiating!) Determine a change of variables from x to u. Choose the correct answer below. O A. u= x4 O B. u= ex O C. U=x 5 OD. u = x*ex Write the integral in terms of u. fx ax ax = [(D) au (Type an exact answer. Use parentheses to clearly denote the argument of each function. Evaluate the integral. ( x# exs dx = ] (Type an exact answer. Use parentheses to clearly denote the argument of each function.)