Final answer:
Welsh rarebit is (A) a warm, cheese-based sauce flavored with stout beer, mustard, and Worcestershire sauce, commonly served over toast or as a dip.
Step-by-step explanation:
The Welsh rarebit dip, sometimes spelled as rabbit, is a savory sauce that originated from Wales. Its main ingredient is cheese, typically cheddar, melted and mixed with various other ingredients to add depth and complexity to the flavor.
The most classic version of the Welsh rarebit includes ingredients such as stout beer, mustard, and Worcestershire sauce. These components blend to create a warm, rich, and slightly tangy cheese sauce that is often served poured over toast or as a dip for bread and vegetables.