Explanation : Current allocation of P1P2P3P4 are 3, 4, 2, 1 which is 10 in total. We have 12 total no of resources and out of them 10 are allocated so, we have only 2 resources. There is 5, 5, 3, 2 resources are needed for P1P2P3P4 respectively. So, P4 will run first and free 3 resources after execution. Which are sufficient for P3 So it will execute and do free 5 resources. Now P1 and P2 both require 5 resources each So we can execute any of them first but we will give priority to P1. The execution order will be P4P3P1P2. SO, option (C) is correct.
Explanation : A scheduling Algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero (lowest priority). The scheduler reevaluates the process priority for every ‘T’ time units and decides next process to be scheduled. If the process have no I/O operations and all arrive at time zero, then the scheduler implements Round Robin Scheduling criteria. So, option (B) is correct.