Final answer:
The function that villi do not perform is moving the products of digestion by peristalsis; rather, villi increase the surface area available for nutrient absorption and help regulate nutrient absorption.
Step-by-step explanation:
The question pertains to the functions of villi in the small intestine. The correct answer is that villi do not move the products of digestion along by peristalsis; this is the function of the muscles in the intestinal wall, not the villi. The villi are responsible for increasing the surface area available for the absorption of nutrients, facilitating the efficient transfer of nutrients from the digested food into the bloodstream. They also have a role in regulating nutrient absorption and selecting specific nutrients for absorption due to the presence of different transporters and enzymes. Villi and the smaller microvilli are essentially folded in the small intestine lining that increases surface area to maximize nutrient absorption.