Which government department is responsible for collecting taxes and enforcing tax laws?

The United States Department of the Treasury, particularly through the Internal Revenue Service (IRS), is tasked with the responsibility of collecting federal taxes and enforcing tax laws. This agency administers the tax code, ensuring compliance by individuals and businesses, and has the authority to conduct audits and implement penalty measures for non-compliance.

The IRS is also responsible for issuing tax refunds and providing guidance on tax-related matters, which plays a critical role in the overall functioning of the nation's economy. This function is essential for funding government operations and various programs that benefit the public.

Conversely, other agencies mentioned, such as the Securities and Exchange Commission (SEC), regulate securities markets; the Federal Reserve Board (FRB) manages monetary policy; and the North American Securities Administrators Association (NASAA) coordinates state-level regulation of the securities industry. Therefore, understanding the specific roles of these agencies clarifies why the Department of Treasury/IRS is the correct choice for tax collection and enforcement.