Absorption of digested food chiefly occurs in-

Correct Answer: C

Rationale: The small intestine is the main site for nutrient absorption.

Correct Answer: B

Rationale: Fatty acids are absorbed into lacteals and enter the lymphatic system, not the hepatic portal vein.

Correct Answer: C

Rationale: Vitamin B12 is essential for the maturation of red blood cells and DNA synthesis.

Correct Answer: D

Rationale: Proteases, such as pepsin, function optimally in the low pH environment of the stomach.

Correct Answer: D

Rationale: The hepatic portal system transports nutrient-rich blood from the GI tract to the liver for processing and detoxification before entering systemic circulation.