In broad terms the difference between microeconomics and macroeconomics is that

A) they use different sets of tools and ideas.
B) microeconomics studies decisions of individual people and firms and macroeconomics studies the entire national economy.
C) macroeconomics studies the effects of government regulation and taxes on the price of individual goods and services whereas microeconomics does not.
D) microeconomics studies the effects of government taxes on the national unemployment rate.

B