CUSTOMER In table CUSTOMER, CID is the primary key (Customer ID). RENTALS In the table RENTALS, RTN provides the rental number (the primary key), CID is the customer's unique id, PICKUP is the city where the car was picked up, and Return is the city where the car was returned. RENTCOST RENTCOST shows the base cost of renting a given MAKE for one day. CITYADJ If the return city of table RENTALS is the one listed in table CITYADJ, the cost of the rental is multiplied by FACTOR and by DAYS shown in table RENTLENGTH below. RENTLENGTH RENTLENGTH shows the number of days for the rental number (RTN) shown in table RENTALS. In a database used in reality, this table would be merged with the RENTALS table. SELECT CID, CNAME FROM CUSTOMER WHERE EXISTS (SELECT CID FROM RENTALS WHERE CUSTOMER.CID = RENTALS.CID AND PICKUP = 'CARY') The execution of this query lists the following CNAMEs:

BLACK, GREEN, JONES, MARTIN, SIMON

BLACK, JONES, MARTIN

BLACK, GREEN, JONES, MARTIN, SIMON, VERNON

BLACK