You are developing a Windows Store app. You configure the app to allow a free trial period. You
need to prompt the user to purchase the full version of the app when the trial period expires. What
should you do?
A.
Call the getAppReceiptAsync( ) method of the Windows.ApplicationModel.Store.CurrentApp
object.
B.
Call the getProductReceiptAsync( ) method of the Windows.ApplicationModel.Store.CurrentApp
object and provide the app’s product ID as an argument.
C.
Call the requestProductPurchaseAsync( ) method of the
Windows.ApplicationModel.Store.CurrentApp object and provide the app’s product ID as an
argument.
D.
Call the requestAppPurchaseAsync( ) method of the
Windows.ApplicationModel.Store.CurrentApp object.
To buy the app you have to implement an in-app purchase (Source: http://code.msdn.microsoft.com/windowsapps/Licensing-API-Sample-19712f1a). So the correct method will be “requestProductPurchaseAsync” and not “getProductReceiptAsync”. Source: http://msdn.microsoft.com/en-US/en-en/library/windows/apps/hh779780.aspx