Which of the following terms refers to a type of herbal or aromatic substance used in cocktails?

Bitters are a concentrated herbal preparation used primarily in cocktails, and they provide a complex flavor profile that enhances the drink. Typically made by infusing various herbs, spices, and botanicals in a base of alcohol, bitters are characterized by their bitter flavor, which balances the sweetness and acidity of many cocktails. The use of bitters dates back centuries, originally applied as medicinal tonics before becoming a staple in mixology.

Infusions, while related, refer to the process of steeping herbs or flavors in a liquid, often used to create flavored spirits or syrups rather than being a standalone cocktail ingredient. Neat describes a serving method where a spirit is poured straight from the bottle, without any mixers or ice, and does not pertain to herbal substances. Tinctures are concentrated liquid extracts made by soaking herbs in alcohol, but they are more specific than bitters, often not formulated for direct use in cocktails. Thus, bitters represent the quintessential aromatic substance utilized in cocktail crafting, which is why it is the correct answer.