Which of the following is a common type of BBQ sauce?

All of the options listed—tomato-based, mustard-based, and vinegar-based sauces—are widely recognized types of BBQ sauce. Each type brings its own unique flavor profile, influenced by regional preferences and the types of meats they are typically paired with.

Tomato-based sauces are particularly popular in many parts of the United States, especially in areas like Kansas City. They often feature a sweet and tangy flavor profile, made from ingredients such as ketchup, brown sugar, and various spices.

Mustard-based sauces are prevalent in regions like South Carolina. These sauces are characterized by their bright yellow color and slightly tangy flavor, usually incorporating yellow mustard, vinegar, and spices.

Vinegar-based sauces, often found in North Carolina barbecue, highlight a sharp, tangy taste that complements the smokiness of the meat. They typically consist of vinegar, red pepper flakes, and other spices, creating a more acidic sauce that enhances the flavors of the meat without overpowering them.

Since all these sauces are commonly used in BBQ, they each contribute to the diverse world of barbecue flavors, making "all of the above" the correct choice.