Solution

The correct answer is A-II, B-III, C-I, D-IV.

Key Points

• Short Term Scheduler: Selects which process should be executed next and allocates CPU time.
• Medium Term Scheduler: Manages the degree of multiprogramming by swapping processes between main memory and disk storage.
• Long Term Scheduler: Determines which processes are added to the system for execution and places them in the ready queue.
• I/O Scheduler: Orders the input/output requests from processes waiting for I/O operations.

Additional Information

• Schedulers are integral to operating systems for process management and optimization.
• The short-term scheduler operates frequently, deciding which process gets CPU time.
• The medium-term scheduler helps reduce overhead by swapping out processes temporarily.
• The long-term scheduler controls the admission of processes into the system, influencing the degree of multiprogramming.
• The I/O scheduler optimizes the sequence of I/O operations to improve performance and reduce wait times.