Which approach should you recommend?

You are designing a SharePoint 2010 application that allows users to enter contact information into a form.
You need to design the application so that it displays a dialog box prompting users to validate their contact information before the data is saved.
Which approach should you recommend?

A.
Create an application page that calls the SP.UI.ModalDialog class.

B.
Create an application page that calls the SP.UI.PopoutMenu class.

C.
Create a Web Part that calls the Message Box class.

D.
Create a visual Web Part that calls the SP.UI.PopoutMenu class.