(a) Explain the difference between the two scheduling policies in terms of how the process is selected for execution. (1) Shortest Process Next and Shortest Remaining Time [2 marks] (ii) First Come First Serve and Round Robin [2 marks] (6) Five process A, B, C and D has their arrival and service times given in the table below. Draw the scheduling diagram to illustrate the execution of the processes and find the average waiting time for each of the scheduling policies. Process Arrival Time Service Time A 5 2 0 B 4 3 4 D 4 2 (1) Highest Response Ratio Next [4 marks] (ii) Round Robin (time quantum = 2 unit of time) (4 marks