du u-7 Describe the most appropriate substitution case and the values of u and du. Select the correct choice below and fill in the answer boxes within your choi , so that'dv = () du. A. Substitute u for the quantity in the denominator. Let v= B. Substitute u for the quantity under the root. Let v=u-7, so that dv = (1) du. C. Substitute u for the quantity in the numerator. Let v = Use the substitution to evaluate the integral. so that dv= du.