Which node type is added to support this Avamar multi-node server?

A company needs to increase the capacity of an existing Dell EMC Avamar multi-node server with Gens 3.9 TB storage nodes. They want to add three new storage nodes to the server.

Which node type is added to support this Avamar multi-node server?
A . Gen4 3.9 TB
B . Gen4S M600
C . Gen4S M1200
D . Gen4S M2400

Answer: A