4-33. Figure 4-33 shows an EER diagram for a simplified credit card environment. There are two types of card accounts: debit cards and credit cards. Credit card accounts accumu- late charges with merchants. Each charge is identified by the date and time of the charge as well as the primary keys of merchant and credit card. a. Develop a relational schema. b. Show the functional dependencies. c. Develop a set of 3NF relations using an enterprise key. Ho FIGURE 4-33 bank cards CUSTOMER Customer ID Cust Name Cust Address Holds CARD ACCOUNT Account ID Exp Date Card Type MERCHANT Merch ID Merch Addr Card Type "D" "C" DEBIT CARD Bank No CREDIT CARD Cur Bal IH CHARGES Charge Date Charge Time Amount