Which three demonstrate an “is a” relationship？（） 

A.public class X {  }     public class Y extends X { }

B.public interface Shape { }     public interface Rectangle extends Shape{ }

C.public interface Color { }     public class Shape { private Color color； }

D.public interface Species { }     public class Animal { private Species species； }

E.public class Person { }    public class Employee {      public Employee（Person person） { }

F.interface Component { }     class Container implements Component {   private Component[] children； }