Which two steps are mandatory before upgrading VMware Cloud Director appliances from 10.1 to 10.2?

Which two steps are mandatory before upgrading VMware Cloud Director appliances from 10.1 to 10.2? (Choose two.)
A. Take a snapshot of the entire VCD appliances cluster.
B. Take a snapshot of the primary VCD appliance.
C. Take a snapshot of the standby VCD appliance.
D. Change the database failover from Manual to Automatic.
E. Change the database failover from Automatic to Manual.