Answer:
D. Optimization, Equilibrium and Empiricism.
Step-by-step explanation:
Economics is based on three key concepts which are Optimization, Equilibrium and Empiricism. Optimize is the first principle which means people will select best available option. Second important principle is that economy is always in a state of equilibrium which means if one gains the other also gets best available value. Third concept is that economists use data to make policies. The situation given in the scenario follows all the key concepts of economy.