The Cells Lining the Small Intestine Have Projections into the Lumen

The cells lining the small intestine have projections into the lumen of the intestine. These projections, combined with the highly folded layering of cells lining the lumen, function to

A) facilitate countercurrent exchange.
B) slow the nerve impulses that trigger peristalsis.
C) decrease the reabsorption of water.
D) increase the surface area for nutrient absorption.
E) increase the rate of peristalsis.