Answer:
The correct answers are:
A) The effects of the Internet on the pricing of used cars.  (Microeconomics)
B) The effect of government regulation on a monopolist's production decisions
. (Microeconomics)
C) The effects of government tax policy on long-term economic growth. (Macroeconomics)
Explanation:
The field of economics is usually broken down into two broad categories: Microeconomics and Macroeconomics. The goal of all economics is to analyze the production and consumption of finite resources like oil, wheat, capital or even labor. Microeconomics observes these issues from an individual or business perspective. Macroeconomics looks at the issues from the perspective of the country as a whole, and the policies affecting the economy. Thus:
A) The effects of the Internet on the pricing of used cars. (Microeconomics)
B) The effect of government regulation on a monopolist's production decisions. (Microeconomics)
C) The effects of government tax policy on long-term economic growth (Macroeconomics)