Ajie sold his house for Rp500.000.000,00 that he bought a year ago for Rp500.000.000,00. He says, “at least I didn’t lose my money on my financial investment.” His economist friend point out that in effect he did lose money, because he could have received at least 5 percent return on the Rp500.000.000,00 if he had bought a bank certificate of deposit instead of a house. The economist’s analysist in this case incorporates the idea of ….

A. normative economics

B. cost productions

C. opportunity cost

D. marginal benefit

E. efficiency