The total amount of goods and services in the economy that will be purchased at all possible price levels is the A. aggregate supply. B. aggregate demand. C. aggregate output. D. aggregate market share.

B. aggregate demand.

Extra: Aggregate demand represents the total demand for goods and services within a particular market. To understand this concept, it's important to know that it includes the sum of all spending by households, businesses, government, and foreign buyers for a country's goods and services, across all price levels during a specific time period. Factors that can shift the aggregate demand curve include changes in consumer confidence, monetary and fiscal policies, exchange rates, and the economic conditions of trading partners.

Contrastingly, aggregate supply is the total amount of goods and services that producers in an economy are willing and able to supply at different price levels. Aggregate output is basically another term for the total production or GDP (Gross Domestic Product) of an economy. Aggregate market share doesn't directly relate to the overall economy's output or demand, but instead refers to the total sales of a company as a proportion of total market sales. In the context of your question, aggregate demand is the correct answer because it specifically refers to the total amount of goods and services that will be purchased at all possible price levels.