The correct answer is a small piece of the overall economy; the economy as a whole.
Microeconomics or price theory analyzes the formation of prices in the market, that is, how the company and the consumer interact and decide the price and quantity of a product or service. It studies the functioning of supply and demand (demand) in price formation.
Microeconomics is concerned with explaining how prices and their factors of production are fixed.
Macroeconomics studies the economy in general by analyzing the determination and behavior of large aggregates such as income and products, price levels, employment and unemployment, currency stock, interest rates, balance of payments and exchange rates. The macroeconomic approach may omit important factors, but it establishes relationships between large aggregates and allows to understand some relevant interactions. Macroeconomics is concerned with short-term aspects such as unemployment, for example.
Macroeconomics has some goals such as increasing the level of jobs, stabilizing prices, distributing income, growing the economy, resolving conflict of objectives.