You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5.  You write the following code fragment. （Line numbers are included for reference only.）  01  02 ID="rfValidator1" runat="server"  03 Display="Dynamic" ControlToValidate="TextBox1"  04  05 >  06  07   08  09  10 ID="ValidationSummary1" runat="server" />  You need to ensure that the error message displayed in the validation control is also displayed in the validation summary list.  What should you do？（）

• A、A
• B、B
• C、C
• D、D