Question 3 (1 points): In lecture, we discussed implementing a mutex that does not consume a lot of CPU running a waiting loop by using a queue of waiting threads and a spinlock. This mutex implementation may Select all that apply A. need to wait briefly to acquire the spinlock (by running a loop that repeatedly checks if the spinlock is free) in order to complete the mutex unlock operation B. return from the mutex lock operation after locking and not unlocking the spinlock C. make a previously runnable thread not runnable from the mutex lock operation