Which of the following is an ingredient in nachos?

Pepper Jack cheese is indeed a classic ingredient in nachos, making it the correct choice. This cheese is a variant of Monterey Jack that includes spicy peppers, which adds both creaminess and a kick of heat to the dish, enhancing the overall flavor profile of nachos. When melted over tortilla chips, it creates a deliciously gooey texture that is essential for a satisfying nacho experience.

In contrast, while pimento cheese can be a tasty dip or spread, it is not traditionally associated with nachos. Curried lentils, though nutritious, are not a common ingredient in this dish and would alter its flavor significantly. Provolone is a cheese that can be used in various recipes but is not standard in nachos, where the preference typically leans towards cheeses that melt well and have distinct flavors, like Pepper Jack.