On a system using non-preemptive scheduling, processes with expected run times of 5, 18, 9 and 12 are in the ready queue. In what order should they be run to minimize wait time?
- A. 5, 12, 9, 18
- B. 5, 9, 12, 18
- C. 12, 18, 9, 5
- D. 9, 12, 18, 5
Answer: B. 5, 9, 12, 18
Explanation: SJF (Shortest Job First) minimizes average waiting time. Order: 5, 9, 12, 18.