Consider the previous problem, only the carriers are larger and capable of holding up to four parts (np = 1, 2, 3, or 4). The loading time TL = 9 + 3np, where TL is in seconds. With other parameters defined as in the previous problem, determine which of the four values of np are feasible. For those values that are feasible, specify the appropriate design parameters for (a) spacing between carriers and (b) number of carriers that will achieve this flow rate.