How Do Economists Define Aggregate Demand

How do economists define aggregate demand?

A) as the total spending by all consumers, business firms, governments, and foreigners in Canada
B) as the total amount that all consumers, business firms, governments, and foreigners wish to spend on all final goods and services at various price levels
C) as the total spending by consumers, business firms, and governments in one year
D) as the total spending by consumers, business firms, and governments on final goods and services