Answer:
Storage Spaces
Step-by-step explanation:
The feature that would best accommodate his needs would be the Storage Spaces feature that has been implemented in the Windows and Windows Server systems. This feature basically takes various hard drives and combines them together, this ultimately acts as copies of each other which protect the data of each one in the unfortunate case that one of the drives tends to fail. This feature also allows you to add more drives to the existing ones with very minimal effort without restricting configuration. Which would solve the needs that are needed in this scenario.