You are a professional level SQL Server 2005 database administrator in an international corporation named Wiikigo. You are experienced in implementing high-availability solutions， monitoring the database server， and design deployment. In the company， you major job is the deployment， maintenance and support of Microsoft SQL Server 2005. You work as a database administrator for your company. There is a database named Inventory on a SQL Server 2005 computer， and the computer is named SQL01. SQL01 is utilized to aggregate manufacturing part numbers from your company’s trading partners. And the company stores the manufacturing part numbers in the Product table in the Inventory database. The company requests the users to deliver data as text files from each trading partner to SQL1 every night. The data should be imported， and no duplicate manufacturing part numbers should exist in the data which is imported from the text files， and the text files are stored in the Inventory database on SQL01. You should cut the effect on your company’s trading partners and your IT department to the least.  Which action should you perform？（）

• A、First， you should import the data from each text file into a staging table. Second， you should write a query to have a HAVING clause contained so as to migrate replicate values before results are inserted into the Product table.
• B、First， you should make sure that each text file is stored in an Extensible Markup Language （XML） file. Second， you should utilize Extensible Stylesheet Language Transformations （XSLT） to automatically migrate replicates before data is imported into the Product table.
• C、First， you should make sure that the unique key values for manufacturing part numbers are utilized by each of your company’s trading partners utilizes. Second， you should import the text files into the Product table.
• D、You should place a unique index on the PartNum column.