Final answer:
The best detail indicating Hall suffered from cerebral edema is his survival overnight on a mountain without extra oxygen, as this condition is associated with high altitude sickness.
Step-by-step explanation:
The detail from Beyond the Limits that BEST indicates that Hall was suffering from cerebral edema is C. Hall survived a night alone on the mountain without extra oxygen. Cerebral edema can be caused by a lack of oxygen at high altitudes, which may lead to disorientation, confusion, and impaired decision-making. The fact that Hall survived alone without extra oxygen suggests he may have experienced the effects of altitude sickness, which might include cerebral edema, affecting his mental and physical state.