-*Which function is used for starting a process?A.B.C.D.wait()exec()exit()fork()-*Which is not one of the major differences between user-level threadsand kernel-level threads?A.B.One user-level thread can be only mapped be one kernel thread.User threads are scheduled by the thread library and the kernelschedules kernel threads.C.User-level threads are unknown by the kernel, whereas thekernel is aware of kernel threads.D.Kernel threads need not be associated with a process whereasevery user thread belongs to a process.-*In operating system, which sturcture is used for controlling andmanaging the process executionA.B.interruptsystem kernelC.D.semaphoreprocess control block+?When a process changes state, which of the following conversion willnot occur?A.B.C.D.Running->ReadyReady->RunningWaiting->RunningRunning->Waiting-*If there are five processes in the system, how many processes at mostmay be under the waiting state at the same time.A.B.C.D.0541-Which one of the followings is not a method for communicationbetween processes.A.B.C.D.sharing memorymessage bufferpipesemaphore operations wait and signal+-*With indirect communication, the messages are sent to and receivedfrom__________.A.B.C.D.supplychanelpipemailbox-*Which information is not included in PCBA.B.C.D.page sizememory addresspriorityprocess ID+-*One process may include many threads. Which one of the followingsis not occupied by only thread?A.B.C.D.thread control blockstackmemory spaceCPU+-In banch system, job scheduling program chooses multiple jobs fromthe job queue and put them intoA.B.C.D.external storagecachememorypool?*The purpose of real-time operating system isA.B.C.utilization ratio of the computer systeminteractivity of the computer systemreliability of the computer systemD.increase speed of s...