Granville Inc. produces three types of IT gadgets. Products A and B are produced using Make-To-Stock (MTS) system, while product C is produced using Make-To-Order (MTO) system. Products A and B are sold in the Singapore market, while product C is exported to the European market. Production data in April 2022 are collected as follows: Production (units) Manpower (# of full-time workers) Machine (# of machine) Raw Materials (S$) Product A 12,000 20 8 450,000 Product B 15,000 5 5 250,000 Product C 2,000 4 2 80,000 Assume that each full-time worker works eight hours a day, five days a week, four weeks a month; each machine operates eight hours a day, five days a week, four weeks a month. a. Measure the single-factor productivity of manpower (unit/hour), single-factor productivity of machine (unit/hour), and single factor productivity of raw material (unit/S$) for the three products. For each type of productivity, which product has the lowest productivity? Do you think the conclusion is reasonable? Why or why not? (18 marks) b. Based on the calculations in (a), do you think the given information is sufficient for the company to reach a conclusion that the overall productivity of one product is greater than the overall productivity of another? Why or why not? If not, what information is still missing? (6 marks) c. Someone argues that using "number of units of product" as output in the productivity calculation is not reasonable. Do you agree with such a claim? Why or why not? Please explain.