Answer:
The answer is C.
Step-by-step explanation:
Macroeconomics is the study of the economy as a whole, unlike microeconomics which is the study of the individual firms/markets.
Macroeconomics focuses on the standard of living, unemployment rate, inflation rate etc. and how this affects the whole economy.
Option A is wrong because it is the microeconomics and not macroeconomics that studies the market and the firm.
Option B and D are wrong because these are for microeconomics