Which of the following is a dangerous BAC level that could potentially lead to death?

A BAC (Blood Alcohol Content) level of .45% is indeed extremely dangerous and could lead to death. At this level, significant impairment of bodily functions occurs, resulting in a high risk of severe alcohol poisoning, respiratory failure, or even coma.

For context, most jurisdictions in the United States have set the legal limit for driving at .08%, which indicates a level of impairment but is not necessarily life-threatening for all individuals. The .20% level represents a significant risk and impairment but is still likely lower than the threshold for death in many cases. A .10% level is also dangerous and indicates that an individual is considerably impaired, however, it is still much lower than the .45% threshold where the risk of death sharply increases. Thus, while all these BAC levels indicate dangerous drinking, .45% is the level that poses the highest immediate risk to life.