Which of the following is an external user of an insurance company's accounting information?

The users of an insurance company's accounting information are categorized as either internal or external.

• Internal users are individuals within the company who use financial information to make decisions for the company. Examples include managers, employees, and the board of directors.
• External users are individuals or entities outside the company who use financial information to make decisions about the company. Examples include investors, creditors, customers, government agencies, and the general public.

Let's evaluate the given options:

• A. A member of the insurance company's board of directors: Board members are part of the company's governance and are considered internal users.
• B. The insurance company's manager of product development: A manager is an employee of the company and is an internal user.
• C. A home office employee of the insurance company: An employee is an internal user.
• D. A policyowner of the insurance company: A policyowner is a customer of the insurance company. Customers are outside the company and use financial information (e.g., to assess the company's financial health and ability to fulfill its obligations) and are therefore external users.

The correct answer is D.

The final answer is $\boxed{\text{D}}$