Washington Written Drivers Permit Practice Test

BAC, which stands for Blood Alcohol Concentration, is expressed as the percentage of alcohol in the blood. This is the correct answer because BAC measures the amount of alcohol in a person's bloodstream, indicating the level of intoxication. The other options (A. Grams per liter of blood, B. Milliliters of alcohol, C. Parts per million in urine) do not accurately represent how BAC is typically quantified and reported.