Which of the following is NOT an ingredient in a Manhattan?

A Manhattan is a classic cocktail that traditionally consists of whiskey (usually rye), sweet vermouth, and bitters. The inclusion of these ingredients creates a balanced flavor profile, with the whiskey providing depth, the sweet vermouth contributing a slight sweetness and complexity, and the bitters enhancing the overall taste with aromatic notes.

Sugar is not a standard ingredient in a Manhattan. While some variations may incorporate sugar or simple syrup to sweeten the drink, the traditional recipe does not include it. Therefore, recognizing the standard components of a Manhattan is crucial for understanding its classic formulation.