Christopher is issued an insurance policy that contains an attached agreement which alters the terms of the policy. This attached agreement is called a(n):

In insurance terminology, an attached agreement that alters the terms of an insurance policy is referred to as an endorsement. Endorsements are used to modify the original insurance contract, providing additional coverage, exclusions, or changes to the policy provisions. They are formal amendments that are typically issued in writing and become part of the insurance policy.

Using endorsements allows both the insurer and the insured to adapt the coverage to better fit the changing needs of the policyholder without creating an entirely new policy. This flexibility is essential in an insurance context, where the circumstances surrounding coverage requirements may evolve over time.

Other terms listed, such as extension, sanction, and restriction, are not standard terms used to describe a modification of an insurance policy. Extensions may refer to broadening coverage but do not inherently indicate a formal modification. Sanctions typically relate to legal penalties or enforcement actions, while restrictions generally imply limitations rather than alterations in terms. Thus, the proper terminology for an attached agreement that modifies insurance terms is endorsement.