Use the following code to answer the question: public class ClassA { public String fieldX; public String fieldY; private int fieldZ; public ClassA() { System.out.println("Class A"); } private void method1() { ... } public int method2() { ... } } public class ClassB extends ClassA { private String fieldA; private String fieldB; public ClassB() { System.out.println("Class B"); } public void method3() { ... } } ClassA objA = new ClassA(); ClassB objB = new ClassB(); Which class is the superclass [superclass]? Which class is the subclass [subclass]?