How are RAID groups organized for the disks in bank A and bank B in the AF-Series array?

How are RAID groups organized for the disks in bank A and bank B in the AF-Series array?
A . They construct a single RAID group if types of disks match.
B . They construct a single RAID group without any conditions.
C . They construct a single RAID group if they are deployed together.
D . They are constructed into separate RAID groups

Answer: C