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 $44,066.96 $78,640.20 $60,947.10 Average investment 314,764.00 262,134.00 406,314.00 a. Machine Ob. Machine Oc. Machines Od Machines and have the same preferred average rate of return.