What happens when a mirrored volume is converted to RAID-5?

A.
All plexes of the mirrored volume are converted to RAID-5.
B.
One plex is converted to RAID-5 and all other plexes are removed.
C.
The number of plexes converted depends on how many columns the RAID-5 volume has.
D.
The number of plexes converted depends on the stripe unit size.