What is the correct power on/off order of the All Flash-Series? (Choose two.)

A. power off the controller shelf first, then the expansion shelves

B. power on controller shelf first, then the expansion shelves

C. power on expansion shelves first, then the controller shelf

D. power off the expansion shelves first, then the controller shelf

Reference: https://www.reddit.com/r/storage/comments/3ii6dt/nimble_array_remote_shutdown_during_power_outage/