7) After the completion of one I/O operation requested by the process, the process state will be changed A) from waiting to ready B) from running to ready C) from running to waiting D) from ready to running 8) In which of the following scenarios does the system switch from user mode to kernel mode? I. Divide an integer by zero. II. Access the data in a file with the read () system call. A) Only I. B) Only II. C) Both I and II. D) Neither of the two scenarios