Given the file Magnet.java shown, which of the marked lines can you independently insert the line var color; into and still have the code compile? 

// line al public class Magnet { // line a2 public void attach() { // line a3 } // line a4 } A. a2 B. a3 C. a2 and a3 D. al, a2, a3, and a4 E. None of the above