Write an iterated integral for dA over the region R described to the right using R a. vertical cross-sections, b. horizontal cross-sections. y = x y=x6 X . . . .. a. Write the correct iterated integral using vertical cross-sections. Select the correct answer below and fill in the answer boxes to complete your choice. OA. J Jax dy 00 OB. J J dy dx 00 b. Write the correct iterated integral using horizontal cross-sections. Select the correct answer below and fill in the answer boxes to complete your choice. OA. J J dy dx 00 OB. [ dx dy 00