Which of the following best describes the function of health insurance?

The function of health insurance is best described as providing financial protection against high medical expenses. Health insurance is designed to help individuals manage the potentially overwhelming costs of healthcare by sharing the financial burden of medical services. This includes covering a significant portion of medical expenses, such as hospital stays, surgeries, and preventive care, which can otherwise be prohibitively expensive.

While health insurance does help reduce out-of-pocket costs for medical services, it does not cover all costs associated with healthcare under every circumstance. Therefore, it is not accurate to say that health insurance covers all costs unconditionally. Similarly, health insurance does not eliminate the need for out-of-pocket expenses entirely; most plans require users to pay deductibles, copayments, or coinsurance. Furthermore, health insurance does not guarantee access to every medical service without limits, as plans typically have networks of providers, exclusions, and certain conditions that must be met for coverage to apply.

In essence, the primary function of health insurance is to provide a safety net for individuals against the financial strain of high healthcare costs, which aligns directly with option B.