What should be done to correct the following code?

            public class exam {
              float mark;
              public static void main(String[]arg){
                float aCopyofMark;
                exam e = new exam();
                System.out.println( e.mark + aCopyofMark);
              }
             }
          

• Change float mark; to static float mark;
• Delete exam e = new exam();
• This is a correct code.