Answer:
A. The business cycle
Explanation:
A period of macroeconomic expansion followed by a period of macroeconomic contraction is known as a business cycle. Like the name suggests, a business cycle is a cycle of highs and lows in economic activities.
There are periods of expansion which is often characterized by economic growth, leading to creation of more jobs, robust middle class etc and contraction which is characterized by loss of jobs, shrinking middle class etc in a business cycle.
Other periods of a business cycle may include peak, trough etc.
