Using c#, create a .NET Windows Forms Applications GUI where when Subscribe button is clicked, an object of SendViaEmail or/and an object of SendViaMobile is/are instantiated , and should be added to corresponding collection(s) if the email or/and mobile has/have not been subscribed before; finish the subscription.

When UnSubscribe button is clicked, removed the corresponding object of SendViaEmail or/and an object of SendViaMobile from corresponding collection(s) if the email or/and mobile has/have subscribed before; finish unsubscription. It should validate email, validate mobile, publish notification. It should also use two collections to hold SendViaEmail objects and SendViaMobile objects respectively.