Consider the LIBRARY relational database schema description provided below which is used to keep track of books, borrowers, and book loans. The relations are: • BOOK (BookID, Title, PublisherName) • BOOK_AUTHORS (BookID, AuthorName) • PUBLISHER (Name, Address, Phone) • BOOK_COPIES (BookID, BranchID, NumberOfCopies) • BOOK_LOANS (BookID, BranchID, CardNumber, DateOut, DueDate) • LIBRARY_BRANCH (BranchID, BranchName, Address) • BORROWER (CardNumber, Name, Address, Phone) 1. Consider the schema given above: (a) (5 points) Give a primary key for each relation. Are there any relations for which there is an alternate candidate key that you have not chosen as the primary key? If yes, mention the relations, candidate keys and the reason (if any) for your choice of the primary key. (b) (10 points) State all referential integrity constraints that should hold on these relations.