What type of agent exclusively represents one insurer or a group of related insurers?

The answer is correct because a type of agent that exclusively represents one insurer or a group of related insurers is known as a captive agent. These agents are typically contracted to work with a specific insurance company and can only sell that company's products. This structure allows the insurer to have direct control over the sales process and ensures that the agent is fully knowledgeable about the products they sell, as they are not spread across multiple companies.

In contrast, independent agents work with multiple insurance companies, giving them the flexibility to offer a wider range of products to their clients. Exclusive agents can be confused with captive agents, but they often represent only one insurer and may have a different contractual arrangement. General agents, on the other hand, manage several agents and have broader responsibilities, but they do not specialize in representing a single insurer in the way that captive agents do. This distinction is crucial in understanding the role of different types of insurance agents in the industry.