Answer:
1) Circular Folds
2) Villi
3) Microvilli.
Explanation:
Small intestine is one of the most important organ of the body and plays n important role in the process of digestion. The dedenum, jejenum and ileum are the parts of small intestine.
The small intestine has villi that helps in increasing the surface area for digestion and absorption. The circular folds has the highest diameter and large in the structure than the villi and microvilli. Microvilli has the smallest structure among the villi and microvilli.
Thus, the order are option (c), (b) and (a).