An oil company is planning to install a new pipeline to connect storage tanks to a processing plant 1500 m away. Both 120 mm and 180 mm pipes are being considered. For this analysis, the company will use an annual interest rate of 10%. Annual maintenance and pumping costs may be considered to be paid in their entireties at the end of the year in which their costs are incurred. If the annual benefit for the 180 mm pipe is exist2000 and the annual benefit for the 120 mm pipe is exist1500, using a B/C ratio analysis what pipe should you choose? You must show your work to receive any points. a. 120 mm b. 180mm