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 */ } }

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 3 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 }.