The correct answer is C. Execution time.
Execution time is the amount of time it takes for a computer to execute a program or command. It is measured in milliseconds or microseconds.
Delay time is the amount of time it takes for a computer to respond to a request. It is measured in seconds or fractions of a second.
Real time is a term used to describe a system that responds to input immediately. For example, a real-time system might be used to control a machine tool or to monitor a patient’s vital signs.
Down time is the amount of time that a computer is not available for use. It is usually caused by a hardware or software failure.
E is not a valid option.