请教一道SCJP题目
题目是：  Assuming that interrupted exception has not been thrown and that"aliva Thread" is a runnable thread,which three guarantee that a thread will leave the running state?
A  yield()
B  wait()
C notify()
D notifyAll()
E sleep(100)
F aliveThrea.join()
G Thread.killThread()  我考的是java 6   自己选了ABE  这是模拟题  
但是答案显示错误  可以指点一下吗？谢谢
急！！！

应是BEF
A是错的，因为yield()没有停止当前线程，yield()只能使同优先级的线程有执行的机会。