This question refers specifically to Protected Maintenance Mode (PMM), which is the standard operational procedure for node maintenance.

Allows for node hardware upgrades without disrupting operations (Option A): This is the primary business benefit. By placing a node in PMM, you can power it down to replace a failed DIMM, upgrade a CPU, or update firmware. The cluster continues to serve I/O to applications without downtime.

Automatically replicates data to other nodes (Option B): This is the technical mechanism that makes PMM safe. When PMM is requested, the PowerFlex system identifies the data chunks residing on that node. It proactively copies (mesh-mirrors) that data to other available nodes in the cluster before the node is allowed to go offline. This ensures that even while the node is down for maintenance, the cluster retains full data redundancy (usually 2 copies).

Option C is a side effect but not the primary "benefit" compared to data safety. Option D is incorrect; maintenance mode consumes resources for rebalancing/replication and does not speed up deduplication.