Use the general slicing method to find the volume of the following solid. The solid whose base is the region bounded by the curve y=6(sqrt(cosx)) and the​ x-axis on -pi/2, pi/2
​, and whose cross sections through the solid perpendicular to the​ x-axis are isosceles right triangles with a horizontal leg in the​ xy-plane and a vertical leg above the​ x-axis.

Set up the integral that gives the volume of the solid. Use increasing limits of integration. Select the correct choice below and fill in the answer boxes to complete your choice.