Use substitution to find the indefinite integral. 1 1- 1) e 401 - 201 de Describe the most appropriate substitution case and the values of u and du. Select the correct choice below and fill in the answer within your choice. O A. Substitute u for the exponent on e. Let u = , so that du = ( ) dt. O B. Substitute u for the quantity in the denominator. Let u = , so that du = ( ) dt. O C. Substitute u for the quantity under a root or raised to a power. Let u = , so that du = ( dt