Elevations on the tongue which provide a rough texture are known as what?

The correct answer is papillae. Papillae are small, nipple-like projections on the surface of the tongue that contribute to its rough texture. They play a significant role in the sensory perception of taste and in manipulating food during mastication. There are different types of papillae, such as fungiform, circumvallate, and filiform, each of which serves various functions related to taste and texture.

Other terms listed refer to different structures. Villi are finger-like projections found in the intestines and are involved in nutrient absorption, not relevant to the tongue. Folds generally refer to structures or surfaces that have been bent or pleated and are not specific to the tongue's anatomy or function. Filaments, while they can refer to hair-like structures, are not typically associated with the texture of the tongue as papillae are, and they do not serve the same functions related to taste perception.