The social changes in the united states in the 20th century gave rise to environmental laws concerned primarily with

The answer that best completes the statement above is this: reducing pollution caused by industry. This is the reason that social changes were made during the 20th century in the United States and led to the enforcement of environmental laws. It was during this time that businesses are mostly run by factories and these are the main sources of different types of pollution. Since then, it has been regulated due to the strong enforcement of environmental laws.