In the formation of an insurance contract, the acceptance generally occurs when the insurer accepts an application. This means that option D, "When the insurer accepts an application," is the correct answer.
When an individual applies for insurance coverage by submitting a completed application to the insurance company, the insurer reviews the application. If the insurer decides to approve the application based on factors such as risk assessment, premium determination, and policy conditions, they formally accept the application. This acceptance signifies the establishment of the insurance contract between the insurer and the insured.
Receiving the policy (option A), approval by an underwriter of the insurer (option B), and the mere receipt of a request by the insurer (option C) are all important steps in the insurance process, but the crucial moment of acceptance, solidifying the contract, occurs when the insurer formally accepts the application.