Consider the 3 processes, P1, P2 and P3 shown in the table. The completion order of the 3 processes under the policies FCFS and RR2 (round robin scheduling with CPU quantum of 2 time units) are

### 1. First-Come First-Served (FCFS):

• At $t = 0$, P1 arrives and runs until completion at $t = 5$.

• At $t = 5$, P2 (arrived at $t = 1$) runs until completion at $t = 5 + 7 = 12$.

• At $t = 12$, P3 (arrived at $t = 3$) runs until completion at $t = 12 + 4 = 16$.

Completion order for FCFS:P1, P2, P3

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### 2. Round Robin with Quantum = 2 (RR2):

• At $t = 0$: Ready queue: [P1]. P1 executes for 2 units (time $0 \to 2$, remaining = $3$). During this time, P2 arrives at $t = 1$.

• At $t = 2$: Ready queue: [P2, P1]. P2 executes for 2 units (time $2 \to 4$, remaining = $5$). During this time, P3 arrives at $t = 3$.

• At $t = 4$: Ready queue: [P1, P3, P2]. P1 executes for 2 units (time $4 \to 6$, remaining = $1$).

• At $t = 6$: Ready queue: [P3, P2, P1]. P3 executes for 2 units (time $6 \to 8$, remaining = $2$).

• At $t = 8$: Ready queue: [P2, P1, P3]. P2 executes for 2 units (time $8 \to 10$, remaining = $3$).

• At $t = 10$: Ready queue: [P1, P3, P2]. P1 executes for its remaining 1 unit (time $10 \to 11$). P1 finishes at $t = 11$.

• At $t = 11$: Ready queue: [P3, P2]. P3 executes for its remaining 2 units (time $11 \to 13$). P3 finishes at $t = 13$.

• At $t = 13$: Ready queue: [P2]. P2 executes for its remaining 3 units (time $13 \to 16$). P2 finishes at $t = 16$.

Completion order for RR2:P1, P3, P2

Thus, the correct option is (C).