A. is the sum of a firm's short run average cost curves. B. shows the lowest average cost facing a firm as it increases output changing both its plant and labor force. C. initially rises when output increases and then falls when output increases. D. always falls as output increases. E. always rises as output increases.

Jason is looking for an engagement ring to offer his girlfriend. he has found a similar ring at each of four different jewelry stores. he doesn't have enough money to pay for the ring in cash, so he is planning on opening a line of credit (credit card) at the store he ends up buying the ring from. the chart below outlines the difference in the price of the rings the different stores offer as well as the difference in credit options. jason plans to pay off the ring purchase in 36 months. according to the information in the table, which of the jewelry stores will have the cheapest ring in the end?