Which renewal option does NOT guarantee renewal and allows the insurance company to refuse renewal of a policy at any premium due date?

The option that does not guarantee renewal and allows the insurance company to refuse renewal of a policy at any premium due date is known as optionally renewable. Under an optionally renewable policy, the insurer has the right to choose whether or not to renew the policy at each renewal date. This means that while the insured may pay the premiums on time, the insurer can decide not to renew the policy for various reasons, such as changes in underwriting guidelines or risk assessment.

In contrast, conditionally renewable policies require the insurer to renew the policy under certain conditions, while guaranteed renewable policies mandate the insurer to renew regardless of any changes in health or risk, provided premiums are paid. Noncancellable policies offer the most security to the insured, as they guarantee renewal at the same premium rate for a specified period, with no right for the insurer to cancel or change the terms. Thus, optionally renewable policies provide the least security in terms of renewal rights for the insured.