How much beverage alcohol is considered equivalent to one standard drink?

The correct choice defines one standard drink in terms of volume and alcohol content consistently across various types of alcoholic beverages. A standard drink is characterized by a specific amount of pure alcohol, which is generally recognized as approximately 14 grams. This amount is typically represented by different serving sizes of beer, distilled spirits, and wine.

For example, a 12-ounce beer (usually around 5% alcohol by volume), 1.5 ounces of distilled liquor (commonly around 40% alcohol), and a 5-ounce glass of wine (which tends to have about 12% alcohol) each contain roughly the same amount of pure alcohol. This consistency is crucial for understanding safe drinking limits and making informed choices about alcohol consumption.

The other options do not align with this standardization, either by offering larger serving sizes that exceed the equivalent alcohol content of one standard drink or by providing non-standard measurements that can lead to confusion about what constitutes a moderate amount of alcohol. Therefore, option A accurately reflects the widely accepted definition of a standard drink.