请阅读下面程序 public class ThreadTest public static void main(String args[])throws Exception int i=0: Hello t=new Hello(); _________; while(true) System.out.println( Good Morning +i++); if(i==2&&t.isAlive()) System.out.println( Main waiting for Hello! ); t.join(); 等待t运行结束 if(i==5)break;) class Hello extends Thread int i; public void run() while(true) System.out.println( Hello +i++); if(i==5)break; 为使该程序正确执行,下画线处的语句应是( )。
A.sleep()
B.yield()
C.interrupt()
D.start()