Final answer:
The IRS is responsible for administering and enforcing the internal revenue laws of the United States.
Step-by-step explanation:
The question is about the subject of Social Studies. The Internal Revenue Service (IRS) is responsible for administering and enforcing the internal revenue laws of the United States. It is the agency that collects taxes from citizens and ensures compliance with tax laws. The IRS plays a critical role in the government's revenue collection and financing of government expenditures.