What is the process for creating an NFS mount between two servers in the same network zone？（）

A.Export the desired filesystem in the /etc/nfs file， run ’exportfs -a’，create a mount directory on the desired server， and mount the NFS filesystem.
B.Run ’exportfs -a’，export the desired filesystem in the /etc/nfs file，create a mount directory on the desired server， and mount the NFS filesystem.
C.Export the desired filesystem in the /etc/exports file， run ’exportfs -a’，create a mount directory on the desired server，and mount the NFS filesystem.
D.Run ’exportfs -u’，export the desired filesystem in the /etc/exports file， create a mount directory on the desired server，and mount the NFS filesystem.