The correct answer is: C. expert system.
An expert system is a computer program that contains expertise in a particular domain. It is designed to solve problems that would normally require human expertise. Expert systems are typically used in fields such as medicine, law, and finance.
An intelligent planner is a computer program that can plan and execute actions in order to achieve a goal. It is typically used in fields such as robotics and artificial intelligence.
An automatic processor is a computer program that can process data automatically. It is typically used in fields such as data mining and machine learning.
An operational symbolizer is a computer program that can represent knowledge in a symbolic form. It is typically used in fields such as artificial intelligence and knowledge representation.
E. None of the above is not the correct answer because it does not specify a particular type of computer program.