15

Do I have the option to show a custom form if the option button is clicked on Office Menu ?

Yes.

Create a new Ribbon XML and insert lines of code as stated in the sample below :

Sample XML: 

<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui">
   <commands>
     <command idMso= "ApplicationOptionsDialog" onAction="OnActionOptionsButton"/>
   </commands>
   <ribbon startFromScratch="false">
           <!-- Here your XML code is going on -->
   </ribbon>
</customUI>

Create the following Callback function in a standard modul:

Public Sub OnActionOptionsButton(control As IRibbonControl, ByRef cancelDefault)
    DoCmd.OpenForm "frmYourForm", , , , , acDialog
End Sub

See Access sample database "Access-Options"