What will be the output of the following Java program?

class box 
{
     int width;
     int height;
     int length;
} 
 class mainclass 
 {
     public static void main(String args[]) 
     {        
         box obj = new box();
         System.out.println(obj);
     } 
 }

A. A special method to create instances of classes B. A method used for mathematical calculations C. A method to perform string manipulations D. An exception handling mechanism

A. method B. def C. func D. public

A. start() B. main() C. init() D. constructor()

A. Defining multiple methods with the same name in the same class B. Calling methods from another class C. Using methods to load data from a file D. Running methods in parallel threads