You want to create a new shadowset. Which mount sequence reduces the amount of I/O
needed?

A.
$ INITIALIZE /SHADOW=($1$DGA121, $1$DGA122) VOLATILE
$ MOUNT/SYSTEM DSA42 /SHADOW=($1$DGA121, $1$DGA122) VOLATILE

B.
$ INITIALIZE /NEW /SHADOW=($1$DGA121, $1$DGA122) VOLATILE
$ MOUNT/SYSTEM DSA42 /SHADOW=($1$DGA121, $1$DGA122) VOLATILE

C.
$ INITIALIZE /SHADOW= $1$DGA121 VOLATILE
$ INITIALIZE /SHADOW= $1$DGA122 VOLATILE
$ MOUNT/SYSTEM DSA42 /SHADOW=($1$DGA121, $1$DGA122) VOLATILE

D.
$ INITIALIZE /ERASE /SHADOW= $1$DGA121 VOLATILE
$ INITIALIZE /ERASE /SHADOW= $1$DGA122 VOLATILE
$ MOUNT/SYSTEM DSA42 /SHADOW=($1$DGA121, $1$DGA122) VOLATILE