You work as the database administrator at Domain.com. The Domain.com network contains a SQL Server 2005 database server named Certkiller -DB01 that runs on a Windows 2000 Server computer. Certkiller -DB01 hosts a database named CK_Sales. The tables in the CK_Sales database are shown in the following database diagram.

An index named PK_Customers_CustomerID has been created on the Customers table. The index is used extensively throughout the day. Over the last few months, several new pages have been added to the index. Domain.com users complain that the performance queries against the index is very slow. You suspect that fragmentation is affecting query performance. You want to reduce fragmentation. You need to ensure that the index remain online and that no completed work is lost if the operation is interrupted.
exhibit What should you do?