Which of these is a side featuring a taco?

The single taco is identified as a side featuring a taco because it is a standalone item specifically categorized under menu offerings that highlight the taco itself. A side typically complements a main meal and may not be a full meal on its own. The single taco fits this definition as it is a simple, individual serving that can accompany other main dishes.

On the other hand, a taco salad includes multiple ingredients beyond just the taco, and is more of a full meal rather than a side. The bacon shell taco, while innovative, serves as a variant of a taco rather than a side option. Cheesy taco fries, meanwhile, introduce additional elements—fries and cheese—making it inconsistent with the concept of a taco-centric side. Thus, the single taco clearly stands out as a true taco side.