Your aircraft has lost pressurization at 43,000 feet, and you are breathing only 100% oxygen and have an oxygen pressure in the lungs of about 42 mmHg. At what altitude are you physiologically if you were breathing air, and what stage of hypoxia are you in?

A) 30,000 feet, Disturbance
B) 35,000 feet, Critical
C) 40,000 feet, Compensatory
D) 45,000 feet, Indifferent