Which of the following is not a function of the Internal Revenue Service?

The correct choice identifies that providing health insurance is not a function of the Internal Revenue Service (IRS). The IRS is primarily responsible for federal tax administration, which includes several specific functions such as administering tax laws, enforcing tax compliance, and collecting federal income taxes from individuals and businesses. These responsibilities are centered around managing the tax system and ensuring that taxpayers meet their obligations.

In contrast, health insurance is not within the purview of the IRS. While the IRS may have a role in aspects related to taxation of health insurance (like determining affordability under the Affordable Care Act), the agency itself does not provide health insurance services or programs. This distinction clarifies the specific role the IRS plays in revenue collection and tax administration versus the domain of health care, which involves separate agencies and services.