What measurement indicates the amount of alcohol in the bloodstream?

The measurement that indicates the amount of alcohol in the bloodstream is Blood Alcohol Concentration (BAC). BAC is expressed as a percentage and represents the grams of alcohol per deciliter of blood. This measurement is critical for assessing an individual's level of intoxication, which can influence behavior, cognitive function, and physical coordination. Law enforcement often uses BAC to determine if a driver is over the legal limit for alcohol consumption. Understanding BAC is essential in the context of responsible alcohol service and consumption, as it helps staff identify when a customer may be impaired.

Other options provided, such as Alcohol Consumption Ratio and Alcohol Dependency Index, are not standardized measures for assessing immediate intoxication levels and focus on different aspects, such as consumption habits or potential alcohol use disorders. Consumption Per Intake is not a recognized medical or scientific term relevant to alcohol measurement.