I believe the answer is A. Achieving all of the above results.
Reason being because you need a certain amount of oxygen to support your muscles in every activity or your body will shut down.
It can cause massive long term brain damage such as having a foggy brain, some can also lead to problems with your eyesight. But most importantly if receiving a concussion before one is healed can cause severe brain swelling.
The adult human brain contains almost 97% of the body's neural tissue.
No, Your brain is still active ...even when you are sleeping
