Which statement is true about expanding an aggregate from 32-bit to 64-bit in place?

A.
All aggregates are automatically converted from 32-bit to 64-bit with the Data ONTAP 8.1upgrade.

B.
The expansion is triggered by an aggr convert command.

C.
The expansion is triggered by adding disks to exceed 16 TB.

D.
The 32-bit aggregates are degraded and must be Volume SnapMirrored to a new 64- bitaggregates with
Data ONTAP 8.1 upgrade.

Explanation:
http://www.ntapgeek.com/2011/12/how-in-place-expansion-works.html
To upgrade an aggregate in-place, the only available method is to add disks to expand the aggregate to >16TB.