问题：

[单选]

public class X implements Runnable （  
private int x；  
private int y；  
 public static void main（String args） （  
X that = new X（）；  
（new Thread（that）） . start（ ）； 
 （new Thread（that）） . start（ ）；  
）  
 public synchronized void run（ ） （  
 for （；；） （  
 x++；  
 y++；  
 System.out.printIn（“x = “ + x + “， y = “ + y）；  
 ） 
 ）  
 ）  
What is the result？（）

A .  An error at line 11 causes compilation to fail.
B .  Errors at lines 7 and 8 cause compilation to fail.
C .  The program prints pairs of values for x and y that might not always be the same on the same line  （for example， “x=2， y=1”）
D .  The program prints pairs of values for x and y that are always the same on the same line （forexample， “x=1， y=1”. In addition， each value appears twice （for example， “x=1， y=1” followed by  “x=1， y=1”）
E .  The program prints pairs of values for x and y that are always the same on the same line （for example， “x=1， y=1”. In addition， each value appears twice （for example， “x=1， y=1” followed by  “x=2s， y=2”）