The best answer from the available options is proof of loss. In claims practice, a proof of loss is a formal document submitted by the insured setting out the facts and amount of the claim, and it is commonly tied to the insurer’s payment process. In many settlements, the signed claim documentation confirms the amount claimed and supports final payment of the insured loss. A non-waiver agreement does the opposite of releasing obligations; it allows the insurer to investigate while preserving its coverage defences. A reservation of rights letter similarly permits the insurer to continue handling or investigating the claim while reserving the right to deny coverage later. A sworn statement may form part of proof-of-loss documentation, but by itself it is not the standard answer in this option set. Strictly, a separate release is the cleanest document for discharging further obligations after settlement; however, since “release” is not offered, proof of loss is the course-aligned choice that most closely fits the described claims-payment function. References/topics: Claims; proof of loss, claim payment documentation, release of obligations, non-waiver agreement, reservation of rights.