interface IFace{} class CFace implements IFace｛｝ class Bace｛｝ public class Exa extends Bace｛ public static void main(String args[]){ Exa ob = new Exa(); Bace b = new Bace(); Object ol = new Object(); IFace o2 = new CFace(); } ｝选择正确的答案（ ）