Which of the following is true? i) A rational choice is made on the margin. ii) Microeconomics is the study of the national economy while macroeconomics is the study of the global economy. iii) Economists try to understand how the economic world works by testing normative statements.

Suppose that in the free market, where the supply of the foreign currency is equal to demand for that currency, the peso-dollar exchange rate is 4 pesos = $1

Assume the central bank sets an official exchange rate at 3 pesos = $1, we can say that in the official market the dollar is A) overvalued. B) undervalued. C) appreciated. D) None of the above.

The Dodd-Frank law

A) created new regulations for financial markets and firms. B) based compensation of bankers on shareholder value. C) rewarded bankers when market share increased. D) created rules that help create the recent financial crisis. E) removed capital requirements on financial institutions.