Which agency is tasked with the collection and enforcement of federal taxes in the U.S.?

The U.S. Internal Revenue Service (IRS) is the correct answer because it is the designated agency responsible for the administration, collection, and enforcement of federal taxes. The IRS manages tax laws established by Congress and ensures individuals and businesses comply with these regulations. This includes processes for tax filing, processing tax returns, and conducting audits to enforce tax laws effectively.

The U.S. Department of Treasury oversees the IRS but does not directly handle the day-to-day collection of taxes or enforcement measures. The Federal Reserve System is primarily focused on managing the country's monetary policy and regulating banks, rather than tax collection. The U.S. Office of Management and Budget plays a role in budget formulation and government spending but is not involved in tax collection or enforcement activities. Therefore, the IRS is uniquely positioned to fulfill the specific role of tax administration in the federal government.