Options are:
[+] Smoking;
[+] sodium;
[+] Dehydration;
[+] sweating;
[+] death;
[+] birth;
[+] Veins and arteries.;
[+] lack of oxygen;
Q: Fact 1: Brain cells die quickly if their oxygen supply is cut off. Fact 2: Brain atrophy means the brain matter has shrunk, often because brain cells are dying or dead. Given the two facts above, what causes brain atrophy?
A:
lack of oxygen