Given the following code：     public class Person{     int arr[] = new int[10]；  public static void main（String a[]） {     System.out.println（arr[1]）；     }     }  Which statement is correct？（） 

• A、 When compilation some error will occur.
• B、 It is correct when compilation but will cause error when running.
• C、 The output is zero.
• D、 The output is null.