Concept:The total output (national income) is mainly determined by total spending in the economy, known as aggregate expenditure.
Explanation:Total output is measured by national income, which equals total expenditure on final goods and services.
The major determinant of output is the level of total expenditure, comprising consumption, investment, government spending, and net exports.
When total expenditure rises, output rises; when it falls, output falls.
Answer:A. level of total expenditure