In a Cisco Catalyst 6500 Series Switch with redundant supervisors, how is the Cisco IOS image upgraded?

In a Cisco Catalyst 6500 Series Switch with redundant supervisors, how is the Cisco IOS image upgraded?

A.
The active supervisor automatically synchronizes the image to the standby supervisor.

B.
The standby supervisor is removed and reinstalled in the chassis to synchronize images.

C.
The line cards in the chassis are reloaded upon supervisor switchover.

D.
SSO is used to automatically synchronize images between the active and standby supervisors.