How much usable disk space will this array have?

A server consists of two 72GB SCSI drives and four 146GB SCSI drives. All drives are attached to
a RAID controller. The system administrator has decided to configure all six drives in a RAID 5
array. How much usable disk space will this array have?

A.
288GB

B.
360GB

C.
432GB

D.
728GB

Explanation:

One disk is used for parity.
Five disks are used for data.
5 x 72 GB equals 360 GB of data.