Correct option: a. iii. Small intestine
Solution: The complete digestion of food takes place in the small intestine. The carbohydrates get broken into simple sugars such as glucose, fats into fatty acids and glycerol, and proteins into amino acids.
b. Water from the undigested food is absorbed mainly in the
i. stomach ii. Food pipe
iii. Small intestine iv. Large intestine
Correct option: b. iv. Large intestine.
Solution: The large intestine is wider and shorter than small intestine. It is about 1.5 metre in length. Its function is to absorb water and some salts from the undigested food material.