Concept:The professional who studies an existing system to create a computer-based version of it is known as a system analyst.
Explanation:The system analyst first examines the current system carefully to understand how it works.
He or she identifies the existing problems and the needs of the organisation.
After studying the present system, the analyst designs a new system that can be implemented on a computer.
This process includes fact-finding, analysing data, and preparing the system specification.
The system administrator is responsible for managing and maintaining installed systems, not for designing new ones.
The computer programmer writes code for a designed system, while the computer engineer works on hardware.
Therefore, the professional who studies an old system to evolve a computer-based system is the system analyst.
Answer:A. system analyst