If an insurer knowingly fails to enforce a policy provision on one occasion, the insurer...

Comprehensive and Detailed Step by Step Explanation:The principle ofestoppelprevents a party from asserting rights or enforcing terms if their prior actions contradicted such enforcement.

Estoppel (C):If the insurer knowingly disregards a policy provision (e.g., a late premium payment), they may be barred from enforcing it later if the policyholder relied on the prior inaction.

Adhesion (A):Refers to contracts where terms are dictated by one party (e.g., the insurer), not applicable here.

Waiver (B):Occurs when an insurer voluntarily relinquishes a known right but does not necessarily create future obligations like estoppel does.

Subrogation (D):Involves transferring the insured’s claim rights to the insurer after a loss, unrelated to this scenario.

References: Maryland Legal Doctrines on Insurance Enforcement and Contractual Estoppel.