An administrator has a two-node PowerHA cluster in a mutual takeover configuration. He needs to updatefrom 5.5 service pack 1 to 5.5 service pack 2. Which of the following actions will perform the updates with norisk of disruption to applications running in the cluster？（）

• A、Unmanage resource groups on all nodes， update the cluster filesets， start cluster services on all nodes，ensure cluster services stabilize
• B、Update the cluster filesets on all nodes. Run ’refresh -s clstrmgrES’ on one node， wait for the cluster tostabilize， repeat for all other nodes
• C、Unmanage resource groups on one node， update the cluster filesets， start cluster services. Wait for thecluster to stabilize and repeat for all other nodes.
• D、Bring resource groups （RGs） online on all nodes concurrently， bring RGs offline on one node， update thecluster filesets， bring RGs online， repeat for all other nodes