How does the u. s. economy create and destroy millions of jobs each year?   (mark all that apply.)

a. the federal government determines that certain industries are obsolete and closes firms.
b. some businesses are expanding, while others are contracting.
c. when unemployment is high, the federal government hires more workers to offset the effects of unemployment.
d. in the market system, new firms are constantly entering and exiting various industries.

The correct answer is option B and option D.

Explanation:

The US economy is a capitalist or market economy. In such an economy, the firms are constantly entering and exiting various industries. Existing firms exit the industries because of technological change, bad management, bad decisions, adverse shifts in consumers' tastes and preferences.  

At the same time, new firms enter the market or other firms hire new workers because they are doing good because of the opposite reason.  

This expansion and contraction in the business create and destroys millions of jobs each year in the US market.