26. Consider the 3-state process model, with its ready, running, and blocked" states. In pure theory, given 3 states there could be 6 transitions In this case the theoretical transitions would be: ready running 6 3 blocked In practice not all of these are meaningful: those that aren't never occur. For those that do, there is a reason for the occurrence. Choose the answer below that, for the 6 transition possibilities, identifies which ones do not occur and typical causes of those that do. job scheduled job scheduled 1job scheduled 2 tme exhausted I/O terminated does not occur does not occur I/O instiated tine exhausted job scheduled / initiated does not occur 1/0 completed does not occurdoes not occurtime exhausted time exhausted does not occur I/0 completed 1/O initiated does not occur 4 I/O initiated 5. 1/0 completed 6. does not occur 27. The systen calls of an operating system typically: A. Consist of a pre-defined set B. May be made by any process c. Accomplish tasks the calling processes are not allowed to perforn D. All of the above 28. Operating systems maintain a process control block which holds a process array for each process which holds information about that process. A. true B. false 29. Time sharing, contrasted with batch processing, tends to achieve better cPU utilization. A. true B. false