What is the effect of attempting to compile and run this Java program that consists of two class definitions in separate files:
public class One
{
   public One(int theVar)
   {  var = theVar;
   }

   public String testVar()
   {  String s;
      if (var > 10)
      {  s = "Bigger than 10";
      }
      else if (var < 10)
      {  s = "Smaller than 10";
      }
      return s;
   }

   private int var;
}

public class Two
{
   public static void main(String[] args)
   {  One obj = new One(10);
      obj.testVar();
   }
}
(a) The program doesn't compile.
(b) It compiles and, when run, displays "Bigger than 10".
(c) It compiles and, when run, displays "Smaller than 10".
(d) It compiles but, when run, displays an error message.

Select the most appropriate answer.