You work in a company which uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 Enterprise Edition instance. There is a database named DB1 in the instance. A backup of DB1 is performed every day. You have to minimize the size of the full database backup files of DB1.  In the options below, which Transact-SQL statement should you use? （）  

• A、BACKUP DATABASE DB1 TO DISK = 't:/backups/db1.bak'; 
• B、BACKUP DATABASE DB1 TO DISK = 't:/backups/db1.bak' WITH COMPRESSION; 
• C、BACKUP DATABASE DB1 TO DISK = 't:/backups/db1.bak' WITH DIFFERENTIAL; 
• D、BACKUP DATABASE DB1 TO DISK = 't:/backups/db1.bak' WITH COMPRESSION,DIFFERENTIAL;