Which of the following two storage technologies would require that its' block device be attached to an instance before you can perform any filesystem commands? (Choose two.)

Which of the following two storage technologies would require that its’ block device be attached to an instance before you can perform any filesystem commands? (Choose two.)

Which of the following two storage technologies would require that its’ block device be attached to an instance before you can perform any filesystem commands? (Choose two.)
A . SCSI LUN
B . Cinder Volume
C . NFS Filesystem Meta-Volume
D . Direct Object Block Device

Answer: A, B