What is preventing the configuration from being completed?

You are configuring a DD Cloud Tier and ECS system as part of a LTR cloud backup solution. When adding the Cloud Unit in the Data Domain system you cannot connect to the ECS system

What is preventing the configuration from being completed?
A . The namespace used for DD Cloud Tier is applied to a federated VDC instead of a single VDC
B . An object user associated with the DD Cloud Tier namespace is missing
C . ECS software version 2. 2 HotFix 1 is installed on the ECS appliance
D . Two different DD Cloud Units were added as "Dell EMC Elastic Cloud Storage (ECS)”

Answer: B