A two-node cluster provides NFS exports to a variety of UNIX clients. During fallover testing，it is determined that some clients are unable to mount the exported filesystems after fallover，and before node reintegration. It is verified that the filesystems belong to a resource group and are correct in /usr/es/sbin/cluster/etc/exports.  Which of the following may provide a possible solution to this problem？（）  

• A、 Use HWAT for IPAT to provide more reliable NFS serving.
• B、 Use AIX Fast Connect to provide more robust NFS serving.
• C、 Use NFS Cross Mounting to allow both nodes to export NFS properly.
• D、 Use the "Filesystem Mounted before IP Configured" flag to provide more predictable NFS serving.