Final answer:
The four phases of the business cycle are expansion, peak, contraction, and trough.
Step-by-step explanation:
The four phases of the business cycle can be illustrated by a series of alternating expansion, peak, contraction, and trough.
During the expansion phase, the economy experiences increasing economic activity, such as rising GDP, employment, and consumer spending. The peak phase is the highest point of the business cycle, where the economy reaches its maximum output. Then, the contraction phase follows, characterized by decreasing economic activity, such as declining GDP and rising unemployment. Finally, the trough phase is the lowest point of the business cycle, where the economy hits the bottom before starting to recover.