You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5.

You write the following code fragment.

<asp:RadioButton ID=”RadioButton1″ runat=”server” oncheckedchanged=”RadioButton_CheckedChanged”/>
<asp:RadioButton ID=”RadioButton2″ runat=”server” oncheckedchanged=”RadioButton_CheckedChanged”/>
<asp:RadioButton ID=”RadioButton3″ runat=”server” oncheckedchanged=”RadioButton_CheckedChanged”/>

You need to ensure that the following requirements are met:

* Users can select only one RadioButton control at a time.
* The Web page is not reloaded when a RadioButton control is selected.

What you should do?

A.
Add the following attribute for each of the RadioButton controls. GroupName=”group1″

B.
Add the following attribute for each of the RadioButton controls. ValidationGroup=”group1″

C.
Add the following code fragment to the RadioButton_CheckedChanged method. (sender as RadioButton).Checked = true;

D.
Add the following code fragment to the RadioButton_CheckedChanged method.
RadioButton1.Checked = (RadioButton1 == sender);RadioButton2.Checked = (RadioButton2 == sender);RadioButton3.Checked = (RadioButton3 == sender);