Correct Answer:
B. Time-sharing
Multitasking is an extension of time-sharing. Time-sharing is a technique that allows multiple users or multiple programs to share a single CPU by rapidly switching between them. Each user or program gets a small slice of CPU time, creating the illusion that all tasks are running simultaneously. Multitasking applies this concept to a single user running multiple applications concurrently on their system, where the operating system manages the CPU's allocation to each program.
- Multiprogramming is an earlier concept where multiple programs reside in memory, but only one runs at a time until it performs an I/O operation, then another runs. It lacks the rapid CPU switching for interactive use.
- Batch processing executes jobs sequentially without user interaction, typically for large, non-interactive tasks.
- Serial processing means tasks are executed strictly one after another, which is the opposite of concurrent execution.
Therefore, time-sharing is the foundational concept enabling modern multitasking.