Use a change of variables to evaluate the following indefinite integral. [ x+ ( x 5 + 14 ) # dx Determine a change of variables from x to u. Choose the correct answer belo O A. u=x OB. u= (x5 + 14) 4 C. U=X5 + 14 O D. u = 5x4 Write the integral in terms of u. x4 (x5 + 14) 4 dx = - u 5 du Evaluate the integral. x 4 (x5 + 14) 4 dx =[