A.move the line 12 print statement into the foo（） method
B.change line 7 to public synchronized void go（）{
C.change the variable declaration on line 2 to private volatile int x；
D.wrap the code inside the foo（） method with a synchronized（this） block
E.wrap the for loop code inside the go（） method with a synchronized block synchronized（this）{//for loop code here}

A.private synchronized Object o；
B.void go（）{   synchronized（）{/* code here */}
C.public synchronized void go（）{/* code here */}
D.private synchronized（this） void go（）{/* code here */}
E.void go（）{   synchronized（Object.class）{/* code here */}
F.void go（）{   Object o = new Object（）；   synchronized（o）{/* code here */}