(Choose 1 answer)
What happens when a thread calls Down (S) when it wants to enter its critical section, where S is a binary semaphore set to 1?
A. The thread is allowed to enter its critical section and S is decremented.
B. The thread is blocked and added to a queue of waiting threads.
C. The semaphore is set to 2.
D. None of the other choices
Exit 25
