Blood Alcohol Content (BAC) is typically measured in grams per 100 milliliters of blood (g/ 100mL), expressed as a percentage or in permille (parts per thousand). While tolerance varies greatly, often considered potentially lethal due to central nervous system depression leading to respiratory extremely high values. Assuming these options 100mL), any level among these would be far beyond the typical lethal threshold and would undoubtedly cause death in most individuals unless they have developed extraordinary tolerance. Given the options, 2.0% (which is 2000 mg/dL or 20 g/L) is the lowest value listed that is undeniably a lethal level of alcohol in the blood.