You are developing a Windows Store app that displays notifications on the lock screen.
The app must execute a background task when the notification arrives. In addition, the app must
receive push notifications from Windows Push Notification Service (WNS).
You need to use a push notification mechanism that meets the requirements.
Which push notification mechanism should you use?

A.
Toast notification

B.
Raw notification

C.
Tile update

D.
Badge update

Explanation:
http://msdn.microsoft.com/en-us/library/windows/apps/jj676791.aspx