The operating system that allows frequent switching from one task toanother is:a) Batch Processing b) Real Time Processingc) Single User d) Time Sharing

The correct answer is d) Time Sharing.

Time-sharing operating systems allow multiple users or jobs to share the system simultaneously. This is achieved by quickly switching between tasks, which gives the illusion of simultaneous execution. The switching happens so fast that it appears as if all users are being served at the same time. This is different from batch processing where tasks are processed in batches one after the other, and real-time processing which is used for critical systems where tasks are processed immediately in real-time. Single user systems, on the other hand, are designed for one user to do one task at a time.