Following a successful cluster fallover， clstat returns no status， the snmpinfo command hangs. All  Cluster resources appear to be active. What should be done to resolve this problem？（）  

• A、 Restart all cluster nodes.
• B、 Verify that cluster.es.client.rte is installed on all nodes.
• C、 Use chssys -a -d -p -s clcomdES to enable cluster communication.
• D、 Use the /usr/sbin/snmpv3_ssw-1 command to revert SNMP from version 3 to version 1.