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 VDSC instead of a single VDC.
B . Two different DD Cloud Units were added as “Dell EMC Elastic Cloud Storage (ECS)”
C . Other namespaces reside on the same storage pool where the namespace for DD Cloud Tier is created
D . Ports 9020 and 9021 are closed in the firewall between the DD system and the ECS load balancer

Answer: D