ensure user selects radio button before adding information

Good Afternoon folk

I have a userform for inputing information to a spreadsheet using the code below. It works fine however if the user does not select a radio button to select a score its saving the rest without it. How can I ensure the user selects a score,,,, ob10, ob8, ob6, ob4, ob2, obna

Private Sub cmdAdd_Click()

Dim iRow As Long
Dim ws As Worksheet
Dim a As Integer
Set ws = Worksheets("Scorepoints")

iRow = ws.Cells(Rows.Count, 1) _
  .End(xlUp).Offset(1, 0).Row
  
a = MsgBox("Please check all information is correct. Select 'Yes' to save, Select 'No' to change", vbYesNo)
If a = vbYes Then
  Unload Me
Else
  Exit Sub
End If

ws.Cells(iRow, 1).Value = Me.txtpoint.Value
ws.Cells(iRow, 2).Value = Me.txtname.Value
ws.Cells(iRow, 3).Value = Me.txtcomments.Value
ws.Cells(iRow, 4).Value = Me.ob10.Value
ws.Cells(iRow, 5).Value = Me.ob8.Value
ws.Cells(iRow, 6).Value = Me.ob6.Value
ws.Cells(iRow, 7).Value = Me.ob4.Value
ws.Cells(iRow, 8).Value = Me.ob2.Value
ws.Cells(iRow, 9).Value = Me.obna.Value
ws.Cells(iRow, 10).Value = Me.cbhr.Value
ws.Cells(iRow, 11).Value = Me.obone.Value
ws.Cells(iRow, 12).Value = Me.obtwo.Value
ws.Cells(iRow, 13).Value = Me.obthree.Value

  Unload Me
  
  scoreselect.Show
  
End Sub

Many thanks for your help

Private Sub cmdAdd_Click()
Dim iRow As Long
Dim ws As Worksheet
Dim a As Integer
Dim Ctrl As Control
Dim OneSelected As Boolean

OneSelected = False

For Each Ctrl In Me.Controls
    If TypeName(Ctrl) = "OptionButton" Then
        If Ctrl Then
            OneSelected = True
            Exit For
        End If
    End If
Next

If Not OneSelected Then
    MsgBox "At least one score must be selected."
    'Setfocus back to any control you wish.
    Me.cmdAdd.SetFocus
    Exit Sub
End If

'Rest of code here.

If you have more than one group of optionbuttons, then you could test for control names.

For Each Ctrl In Me.Controls
    If TypeName(Ctrl) = "OptionButton" Then
        Select Case Ctrl.Name
        Case "ob10", "ob8", "ob6", "ob4", "ob2", "obna"
            OneSelected = True
        End Select
    End If
Next

You can always set a optionbutton as a default when the userform starts.

Private Sub UserForm_Initialize()
Me.OptionButton1.Value = True
End Sub