se substitution to find the indefinite integral 6x 1 S 3x x 4 dx Describe the most appropriate substitution case and the values of u and du Select the correct choice below and fill in the answer boxe so that du A Substitute u for the quantity in the numerator Let u B Substitute u for the entire quantity in the denominator Let u C Substitute u for the quantity raised to an integer power Let u dx so that du dx so that du dx