What is a primary characteristic of supplemental insurance?

Supplemental insurance is specifically designed to enhance the benefits of primary insurance. This type of insurance provides additional coverage or benefits that fill gaps in the primary policy, helping to cover out-of-pocket costs such as deductibles, copayments, or services that may not be fully covered by the main insurance plan. For instance, supplemental insurance can provide benefits for specific illnesses, critical conditions, or even daily living expenses incurred during a hospital stay. By offering this extra layer of protection, supplemental insurance becomes a valuable resource for individuals looking to ensure comprehensive coverage and financial security in the face of medical expenses. This characteristic is why option B is the correct choice.