What is a standard serving size for a shot of liquor?

A standard serving size for a shot of liquor is 1.5 ounces. This measurement is commonly used in the beverage industry and is recognized in many establishments when serving spirits. The 1.5-ounce shot allows for the proper balance of flavor and alcohol content in mixed drinks and cocktails, ensuring that patrons have a consistent experience regardless of where they are served. This standardization helps bartenders maintain consistent drink recipes and allows customers to gauge their alcohol intake more effectively.

In comparison, the other options represent sizes that are not commonly used for a standard shot. Option A, 1 ounce, is often associated with smaller servings or tasting portions, while 2 ounces and 3 ounces significantly exceed the typical shot size and would be considered larger servings, which could lead to overconsumption if used as a standard measurement.