The beverage associated with "FCBL" is known as what?

The beverage associated with "FCBL" is known as Cold Brew Frappe. This drink combines the smooth, rich flavors of cold brew coffee with the creamy and frothy texture typical of a frappe. By specifically referring to it as a Cold Brew Frappe, it highlights that the base is cold brew coffee rather than traditional brewed coffee or espresso, which distinguishes its flavor profile and enhances the overall experience.

In the context of the other options, a frappe generally refers to a blended coffee drink that might not necessarily use cold brew, while espresso is a concentrated coffee brewed by forcing hot water through finely-ground coffee. The term "Chair Frappe" does not exist in the coffee lexicon, making it less relevant. Therefore, recognizing FCBL as referring to Cold Brew Frappe aligns perfectly with its flavor characteristics and preparation style.