The user base of a three-node cluster has increased. In order to add clustered users to all nodes， which of the following steps should be performed？（）  

• A、 On one of the nodes，add the users via C-SPOC ’Add a User to the Cluster’smit menu.
• B、 Use C-SPOC to synchronize the password files between cluster nodes.
• C、 On all of the nodes，add the users to the /etc/passwd and system security files，and then synchronize the cluster.
• D、 On one of the nodes，add the users to the /tec/passwd and system security files，add home directories，and use cron to automate the movement of system security files between nodes.