Method calling in asp.net

1. Use OnCheckedChanged event (the name of the function to be executed when the Checked property has changed) of Radio Button.

2. Call the same function on that event for all Radio Buttons.

3. In that event, check which radio button is clicked.

4. Show in label about that Radio Button.

Refer - How to use OnCheckedChanged event in RadioButton[^], which gives similar type of requirement.

So, in your aspx, Radio Buttons will look like below.

<asp:RadioButton
             ID="RadioButton1"
             runat="server"
             Text="RadioButton1"
             OnCheckedChanged="RadioButton_CheckedChanged"
             AutoPostBack="true">
</asp:RadioButton>
<asp:RadioButton
             ID="RadioButton2"
             runat="server"
             Text="RadioButton2"
             OnCheckedChanged="RadioButton_CheckedChanged"
             AutoPostBack="true">
</asp:RadioButton>
<asp:RadioButton
             ID="RadioButton3"
             runat="server"
             Text="RadioButton3"
             OnCheckedChanged="RadioButton_CheckedChanged"
             AutoPostBack="true">
</asp:RadioButton>
<asp:RadioButton
             ID="RadioButton4"
             runat="server"
             Text="RadioButton4"
             OnCheckedChanged="RadioButton_CheckedChanged"
             AutoPostBack="true">
</asp:RadioButton>

So, as you can see the function "RadioButton_CheckedChanged" is called for all Radio Buttons' OnCheckedChanged Event.

Now in cs page, do like below.

protected void RadioButton_CheckedChanged(object sender, System.EventArgs e)
{
      if (RadioButton1.Checked)
      {
            // Call function you want to call for "RadioButton1".
            Label1.Text = "You choose: " + RadioButton1.Text;
      }

      if (RadioButton2.Checked)
      {
            // Call function you want to call for "RadioButton2".
            Label1.Text = "You choose: " + RadioButton2.Text;
      }
      
      if (RadioButton3.Checked)
      {
            // Call function you want to call for "RadioButton3".
            Label1.Text = "You choose: " + RadioButton3.Text;
      }
      
      if (RadioButton4.Checked)
      {
            // Call function you want to call for "RadioButton4".
            Label1.Text = "You choose: " + RadioButton4.Text;
      }
}