Which insurance feature allows policyholders to add benefits or coverage options to their existing policy?

The correct answer is that a policy rider allows policyholders to add benefits or coverage options to their existing insurance policy. Riders are additional provisions that can be attached to a standard insurance policy, enhancing the coverage or modifying terms. They provide flexibility and customization for policyholders, enabling them to tailor their insurance plans to better suit their individual needs. For example, common riders include those for critical illness coverage, accidental death benefits, or waiver of premium provisions.

The other options relate to various aspects of insurance but do not specifically pertain to the addition of coverage in the same way. An adjustment clause typically refers to a provision that allows for changes based on certain conditions, while a policy amendment generally indicates a change in the terms of the existing policy rather than an addition. An add-on provision could loosely describe similar concepts but is not the standard term used in the insurance industry to describe enhancements made to a policy. Therefore, policy riders remain the most precise and recognized term for this feature.