Which of the following is required for the proper environment of a storage array?

Halon is a fire suppression agent, used for extinguishing fires, and is not a continuous requirement for the proper operating environment of the array itself.

HVAC (Heating, Ventilation, and Air Conditioning) systems are crucial for maintaining the optimal temperature and humidity levels required for the proper operation of sensitive electronic equipment like storage arrays. Maintaining these conditions prevents overheating and condensation, which can lead to hardware failure and data loss.

Solar panels are a power generation method and are not a direct requirement for the proper environmental conditions needed by a storage array.

Biometric authentication is a security measure for physical access control, not an environmental requirement for the operational integrity of the storage array.