How Is the Small Intestine Well Designed to Do Its

How is the small intestine well designed to do its job?

A) It is very long and has a huge surface area for nutrient absorption into the blood stream.
B) It is quite muscular for mixing food material with enzymes for effective digestion.
C) It is relatively large in diameter for ease of moving food through for digestion.
D) Cells in its walls release bile to aid in the digestion of fats.
E) It is highly acidic inside to kill off any dangerous bacteria we may ingest.