In a closed-loop process control system, what term is used to describe the action of measuring the difference between the actual result and the desired result and using that difference to drive the actual result toward the desired result?

Correct Answer: Option C — Feedback

Feedback is the essential mechanism in closed-loop control where the output of a system is measured and returned to the input. By comparing the actual result to the desired set point, the system can automatically adjust its operation to compensate for disturbances and maintain precise control over the process.