In an operating system, which of the following scheduling algorithms minimizes the average waiting time for all processes? 

The Shortest Job First (SJF) scheduling algorithm minimizes the average waiting time because it schedules processes based on the shortest expected duration. By prioritizing shorter tasks, SJF reduces the time longer processes spend in the queue, thus lowering the overall average waiting time. Why Other Options are Wrong: a) FCFS does not consider process length, which can lead to long waiting times if a long process arrives first. c) Round Robin provides fairness but not efficiency in minimizing waiting time. d) Priority Scheduling focuses on priority rather than process length, potentially causing starvation. e) Multilevel Queue Scheduling is complex and does not aim specifically to minimize waiting time.