阅读下列代码段,选出该代码段的正确的文件名 ( )class A{ void methodl(){ System.out.println('methodl in class A'); }}public class B{ void method2(){ System.out.println('method2 in class B'); } public static void main(String args[]){ System.out.println('main()in class B'); }} A.A.java B.A.class C.B.class D.B.java