An administrator needs to apply a Technology Level update. During the preview install， the output indicates that there is insufficient space in the /usr filesystem. Review of the root volume group indicates there are no available physical partitions， but the /test jfs2 filesystem is only 8% used. 
What is the most efficient method to use the available space in the /test filesystem to apply the update？（）

A.Use chfs to reduce the /test filesystem
B.Use cplv to copy the /test filesystem to a smaller logical volume
C.Use migratepv l to move the /test filesystem to a different volume group
D.Backup the /test filesystem， remove it， and recreate it with a smaller size