When connecting power for switches and storage equipment with two or more redundant power supplies in a rack?

When connecting power for switches and storage equipment with two or more redundant power supplies in a rack?

A.
Power supplies from a single component should be connected to the same PDU

B.
There should be a separate PDU for each device in the rack.

C.
Power supplies from a single component should be connected to different PDUs.

D.
Each rack should have only one PDU.