Which of the following best describes a mutual insurer?

A mutual insurer is best described as an entity owned by policyholders. This structure means that the policyholders are both the customers of the insurance service and the owners of the company. They participate in the profitability of the insurer, often receiving dividends or other benefits based on the company’s performance. In contrast to stock insurers, which are owned by shareholders who may not have any direct association with the insurance products, mutual insurers focus on serving their policyholders' interests rather than maximizing shareholder profits.

The other options mention ownership structures or specific types of insurance. While stock insurers are owned by shareholders, that does not apply to mutual insurers. Likewise, limiting the scope to only life or health insurance does not accurately reflect the broader nature of mutual insurers, as they can provide various types of insurance products beyond just life or health coverage.