将光盘/dev/hdc（挂载点为/mnt/cdrom）卸载的命令是

题目：将光盘/dev/hdc（挂载点为/mnt/cdrom）卸载的命令是

A、umount/mnt/cdrom
B、unmount/dev/hdc
C、umount/mnt/cdrom/dev/hdc
D、unmount/mnt/cdrom/dev/hdc