Answer:
The answer is Brain Stem.
Explanation:
The brain part that we are least consciously aware of is the brain stem and the reason is because of how it operates and it's functions.
The brain stem is the part of the brain that is located at the end and controls the message flow between our body and our brain. It also regulates our physiological processes such as heart rate, blood pressure, breathing etc. without our notice.
I hope this answer helps.
