The correct answer is D. Maintenance support may be difficult to obtain for an expert system.
Expert systems are computer programs that emulate the decision-making ability of a human expert. They are designed to solve complex problems that require a high level of expertise. Expert systems are typically used in fields such as medicine, law, and finance.
Expert systems are expensive to design because they require a large amount of knowledge to be encoded into the system. This knowledge must be obtained from human experts, which can be a time-consuming and expensive process. Once the knowledge has been encoded, it must be tested and refined to ensure that the system is accurate and reliable.
Expert systems are usually designed to run on small general-purpose computers. This is because expert systems typically require a lot of processing power and memory. However, there are some expert systems that are designed to run on specialized hardware.
Maintenance support may be difficult to obtain for an expert system. This is because expert systems are often complex and require specialized knowledge to maintain. Additionally, the knowledge base of an expert system may need to be updated regularly to reflect changes in the world.
In conclusion, the correct answer is D. Maintenance support may be difficult to obtain for an expert system.