"The resources now going into the War on Terrorism and into improved airport security would save more lives if they were invested in medical research." This statement most clearly reflects which of the following?

A. The best test of an economic theory is its ability to predict.
B. There is no such thing as a free lunch--the use of scarce resources always has an opportunity cost.
C. selfishness; if people were not selfish, we could have more of everything.
D. The value of goods can be determined objectively.