Which is valid?

Given:
1. interface Movable {
2. void move();
3. void stop();
4. }
Which is valid?

A.
public class Bicycle implements Movable {
public void move() { /*…*/ }
public void stop() { /*…*/ }

B.
public class Bicycle implements Movable {
void move() { /*…*/ }
void stop() { /*…*/ }

C.
public class Bicycle extends Movable {
public void move() { /*…*/ }
public void stop() { /*…*/ }

D.
public class Bicycle implements Movable {
public void move() { /*…*/ }