Which of the following describes an insurance company authorized to do business in a state?

An alien insurance company is one that is incorporated in a country outside of the United States. While it may operate in a state, it is not defined by its authorization in that state, but rather by its foreign incorporation. Therefore, the term "alien" does not describe a company authorized to conduct business within a specific state.

A foreign insurance company is one that is incorporated in a different state than the one in which it is doing business. Like the alien company, the term "foreign" indicates the location of incorporation rather than its authorization status in a specific state. A foreign insurer may or may not be admitted in the state where it operates.

A nonadmitted insurance company is one that is not licensed to operate in a given state. Such companies are often subject to different regulations and do not have the same protections for policyholders as admitted companies. This term directly contrasts with "admitted" and therefore cannot describe an authorized insurer.