在下列程序的空白处，应填入的正确选项是　　Import java.io.*;　　Pulilc class ObjectStreamTest{　　Publilc static void main(string args[]) throws IOException{　　ObjectOutputStream oos= new ObjectOutputStream　　(new FileOutputStream(“serial.bin”));　　Java.util.Date d= new Java.util.Date();　　Oos (d);　　ObjectInputStream ois=　　new ObjectInputStream(new FileOutputStream(“serial.bin”));　　try{　　java.util.date restoredDate =　　(Java.util.Date) ois.readObject();　　System.out.println　　(“read object back from serial.bin file:”　　+ restoredDate);　　}　　Catch (ClassNotFoundException cnf) {　　System.out.println (“class not found”);　　}　　｝

A．WriterObject

B．Writer

C．ＢufferedWriter

D．WriterObject