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. Estimated average income Average investment Machine A Machine B Machine C $44,607.50 $77,385.00 $73,311.15 318,625.00 257,950.00 488,741.00 Oa. Machine A Ob. Machine C Oc. Machine B Od. Machines B and C have the same preferred average rate of return