A national bookseller wants to keep track of the books each of its stores has in stock. Which of the following is the best design?

a$.$ Use a class Store which contains Book objects

b$.$ Use a class Book which contains Store objects

c$.$ Use a class Store which contains an enumerated type Book

d$.$ Use a class Book which contains an enumerated type Store

e$.$ Use a class BookStore which contains information on the stores and books stored as primitive data.