The production department is proposing the purchase of an automatic insertion machine. It has identified three machines and has asked the accountant to analyze them to determine which one has the best average rate of return. Machine A Machine B Machine C Estimated average income Average investment a. Machine A b. Machine C $40,000 $50,000 $75,000 300.000 250,000 500,000 c. Machine B d. Machines B and C have the same preferred average rate of return.