Which command （without options） would you use to display how much space is available on all mounted partitions？（）

A. xfserv
B. xfs
C. fonts
D. xfstt
E. fserv

A. mount /dev/cdrom /mnt/cdrom
B. mount/dev/cdrom
C. mount -t cdrom /dev/cdrom /mnt/cdrom
D. mount /mnt/cdrom
E. automount /mnt/hdd /mnt/cdrom