Consider the following program: public class Product { private int price; public void setPrice(int theprice) { price = thePrice; }} public class SpecialProduct extends Item { private int discount; public void setDiscount(int theDiscount) { discount = theDiscount; }} public class Main{ public static void main(String[]args){ SpecialProduct product = new SpecialProduct(); }} Which of the following compiles without a problem? Why? a. product.discount = 20; b. product.setDiscount(20); c. product.setPrice(50);