You have a SharePoint Server 2010 server farm. You have an Active Directory user account named
Apps that is used for a large number of Application pools. You need to change the password of Apps
every 30 days. You must achieve this goal using the minimum amount of administrative effort. What
should you do?

A.
Run stsadm.exe and specify the setapppassword operation.

B.
Run stsadm.exe and specify the updatefarmcredintials operation.

C.
From Central Administration, modify the managed accounts settings.

D.
From Central Administration, add Apps to the Delegated Administrators group.

Explanation:
BURGOS MNEMO: “managed accounts settings”
How-To Video: Changing Application Pool Accounts in SharePoint 2010
http://blog.rafelo.com/2010/03/how-to-video-change-application-pool.html