7) can be used to prevent busy waiting when implementing a semaphore. A) semaphore B) Waiting queues C) Mutex lock D) pthread join 8) How many philosophers may eat simultaneously in the Dining Philosophers problem with 5 philosophers? A) 1 B) 2 C) 3 D) 5 9) Mutual exclusion implies that: A) if a process is executing in its their critical sections B) if a process is executing in its critical section, then other processes must be execut their critical sections critical section, then no other process must be executi