4. Answer the questions considering the following case Best-East Yummy Burgers is at present in need of a database for their burger shops. The have wide varieties of burgers, snacks (fries, nuggets), beverage and water. A customer can purchase burgers individually or purchase a combo (with french fries and soft drinks). Besides, a customer may sign up for discount cards to get a loyalty discount. (a) Find appropriate database relation schemas with appropriate attributes. (b) Find Primary and Foreign Keys for all relations (tables). (e) Draw an Entity-Relationship (ER) diagram showing relation relationships. (Note: You are allowed to have necessary assumptions for the above scenario.) = 121