(15) Consider an operating system that provides simple round-robin preemptive scheduling with a 1 second(!) quantum. Suppose there are five user-level jobs, labeled A through E, that require the following amounts of time to run (if they could get the whole CPU to themselves). Given that these five jobs become runnable at very close to the same time and are initially added to the run queue in alphabetical order, answer the Job Time following questions. A You may assume that these are the only five jobs in the system and that B the overhead required for context switches is negligible. Tiebreaker: If a blocked job becomes runnable at the same time another D process's quantum is up, the newly unblocked job is added to the tail of E 5.0 sec. the run queue ahead of the job whose quantum is ending. (a) After how many seconds will each job terminate? Briefly explain your reasoning. (A scheduling diagram is sufficient explanation.) Finish Job Time A 1.0 sec. 4.0 sec. 3.0 sec. 2.0 sec. B D E (b) Now suppose that job C issues an I/O request after each 0.5s it is allowed to run. This I/O request takes 1.5s to complete and causes C to block. Now how long will it take for each job to complete? Again, explain your reasoning. Finish Time Job A B D E