What is an AI system that mimics the decision-making abilities of a human expert using a knowledge base and inference rules called?

An AI system that mimics the decision-making abilities of a human expert is referred to as an expert system. This type of system operates by utilizing a comprehensive knowledge base, which contains facts and rules about a specific domain, and applies inference rules to draw conclusions or make decisions based on that knowledge. The objective of an expert system is to emulate the reasoning capability of a human expert in a particular field, allowing it to solve complex problems or provide advice as a human would.

Expert systems are characterized by their ability to handle uncertainty and reasoning using if-then logic, making them particularly valuable in fields such as medicine, finance, and engineering where expert knowledge is critical. They contrast with other AI methodologies like neural networks, which are primarily used for pattern recognition and machine learning tasks, genetic algorithms which are optimization techniques inspired by natural selection, and reasoning engines, which may be components of expert systems but do not encompass the complete set of features that define an expert system. Thus, the essential role and function of knowledge representation and rule-based reasoning in an expert system clarify why this option is the most appropriate answer.