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. A SQL Server 2005 database is utilized in your company. And a table named Inventory is contained by the database. A column named Price is included by the table. According to the company policy， you cannot reduce more than 10 percent the value in the Price column in any single database operation. Through many kinds of method， the company makes updates to the Price column. For instance， the utilization of ad hoc queries is one of the methods. Since you are the database administrator， you should confirm that this company policy takes its effect. Which action should be performed？（）

• A、A stored procedure should be created， and changes are disallowed by the procedure to the Price column that violates company policy.
• B、On the Price column， a check constraint should be created， and a specified minimum value is required by the check constraint.
• C、A trigger should be created， and changes are rolled back by the trigger to the Price column that violates company policy.
• D、On the Price column， a foreign key constraint is created to a table that valid prices are included.