Which approach should you recommend?

You are planning a feature upgrade for a SharePoint 2010 farm. The original feature with a
version number of 1.0.0.0 is activated in numerous scopes within the farm. You have
designed a new version of the feature, 2.0.0.0, which has been deployed and activated in
many locations but not all. You need to recommend a way to use the object model to
determine if the version number of each feature instance is less than the 2.0.0.0 version in
all of the locations. Which approach should you recommend?

A.
Create a feature receiver that calls the Upgrade method of the SPFeatures class for the
feature.

B.
Programmatically add an <UpgradeActions> section to the Feature.xml file that specifies
the new version number for the feature

C.
Use the object model to update the Version attribute of the feature in the existing
Feature.xml file

D.
Call the QueryFeatures method for each location hosting the feature in the various
scopes.