Which of the following actions is considered an unfair claim settlement practice?

Not investigating claims promptly is considered an unfair claim settlement practice because it directly impacts the efficiency and fairness of the claim resolution process. Insurers have a legal and ethical obligation to investigate claims in a timely manner to provide a fair decision to the insured. When claims are not investigated promptly, it can lead to unnecessary delays, financial strain on the insured, and potential denial of rightful claims. This behavior undermines consumer trust and violates regulations that are designed to protect policyholders from inequitable treatment by insurance companies.

In contrast, timely payment of claims, miscommunication with the insured, and promptly acknowledging claims do not inherently constitute unfair practices as they may still align with the insurer's obligations or be corrected through better communication and customer service. Therefore, prompt investigation is crucial for maintaining equitable treatment in the claims process and ensuring that all parties have their rights respected.