Which of the following actions by a running process will always result in a context switch of the running process, even in a non-preemptive kernel design?
P. Servicing a disk interrupt, that results in another blocked process being marked as ready/runnable.
Q. A blocking system call.
R. The system call exit, to terminate the current process.
S. Servicing a timer interrupt.
(A) P, S
(B) Q, R
(C) Q, R, S