The U.S. economy experienced deflation right after World War I and World War II

What does making decisions "at the margin" mean?

a. that people evaluate how easily a decision can be reversed if problems arise b. that people make those decisions that do not impose a marginal cost c. that people compare the marginal costs and marginal benefits of each decision d. that people always calculate the marginal dollar costs for each decision

________ is the study of an economy as a whole

A) Game theory B) Microeconomics C) Behavioral economics D) Macroeconomics