An organization upgrades a SharePoint 2010 environment to SharePoint 2013. A site
collection is running in SharePoint 2010 compatibility mode.
You must verify that the following features will function correctly when the site collection is
upgraded to SharePoint 2013 native mode:
List views
Custom web parts
Content query web parts
Subsites
You need to ensure that you can perform verification testing without impacting the current
user experience.
What should you do?

A.
Upgrade the site collection to SharePoint 2013.

B.
Perform a database attach upgrade.

C.
Enable the Visual Upgrade option for the site collection.

D.
Generate an upgrade evaluation site collection.