Which statement about BAC is accurate?

Which statement about BAC is accurate?

• A. BAC is a measure of the amount of alcohol in the stomach.
• B. The amount of alcohol in the blood, expressed as a percentage.
• C. BAC can be measured only by a blood sample.
• D. BAC is the percentage of a drink's contents that is alcohol.

Answer: (B)

BAC measures how much alcohol is present in the bloodstream, not in the stomach or in the drink itself. It is expressed as a percentage, reflecting ethanol concentration in the blood (roughly grams of alcohol per 100 milliliters of blood). This makes the statement describing BAC as the amount of alcohol in the blood expressed as a percentage the correct one. The other ideas mix up where the alcohol is measured or what BAC represents: measuring alcohol in the stomach isn’t what BAC captures, and BAC isn’t limited to blood samples since breath tests can estimate it as well. It also isn’t the proportion of a drink that is alcohol—that would describe the beverage’s alcohol content, not the body's blood alcohol level. In practice, typical BAC readings help indicate impairment levels; for example, a BAC around 0.08% is associated with noticeable impairment in many people, and breath tests are a common, quick way to estimate BAC alongside more precise blood tests.

BAC measures how much alcohol is present in the bloodstream, not in the stomach or in the drink itself. It is expressed as a percentage, reflecting ethanol concentration in the blood (roughly grams of alcohol per 100 milliliters of blood). This makes the statement describing BAC as the amount of alcohol in the blood expressed as a percentage the correct one. The other ideas mix up where the alcohol is measured or what BAC represents: measuring alcohol in the stomach isn’t what BAC captures, and BAC isn’t limited to blood samples since breath tests can estimate it as well. It also isn’t the proportion of a drink that is alcohol—that would describe the beverage’s alcohol content, not the body's blood alcohol level. In practice, typical BAC readings help indicate impairment levels; for example, a BAC around 0.08% is associated with noticeable impairment in many people, and breath tests are a common, quick way to estimate BAC alongside more precise blood tests.