The following block of code creates a Thread using a Runnable target: Runnable target = new MyRunnable(); Thread myThread = new Thread(target); Which of the following classes can be used to create the target, so that the preceding code compiles correctly?

• public class MyRunnable extends Runnable{public void run(){}}
• public class MyRunnable extends Object{public void run(){}}
• public class MyRunnable implements Runnable{public void run(){}}
• public class MyRunnable implements Runnable{void run(){}}