Expert systems are characterized by which of the following?

Expert systems are designed to emulate the decision-making abilities of a human expert within a specific field or domain. The characteristic that best describes expert systems is that they often work in very limited domains. This is because expert systems are built using knowledge specific to a particular area of expertise, meaning they can provide detailed insights and problem-solving capabilities in that focused context. The specialized knowledge allows them to perform tasks effectively that may be too challenging for non-experts, but they typically cannot generalize knowledge to other unrelated fields.

In contrast to working across broad domains, expert systems usually rely on a well-defined set of rules, heuristics, or knowledge bases associated with their specific area to provide accurate and efficient solutions. This limitation in their scope is what distinguishes them from more general artificial intelligence systems that aim to operate across a wider range of tasks.