It is the Oxygen Regulator. The oxygen regulator appends to the chamber at the barrel valve. It diminishes the weight of compacted oxygen inside the oxygen barrel to a level more fitting for understanding consideration.
Oxygen Flow control controllers and preserving gadgets are a weight diminishing gadgets intended to direct or bring down oxygen weight from a barrel to levels that can be securely utilized by the patient. A Regulator just directs the spill out of an oxygen chamber.
The answer is (C) Melatonin
I believe it would be the first option because they have less money so if they get sick it would be hard to find a good treatment.
