This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Digestion and Absorption, Subject name: Physiology
Vitamin B12 is mainly absorbed from? 
Select and explain. 
A. Duodenum, B. Jejunum, C. Ileum, D. Colon
C: Ileum
Answer: C: Ileum 
Explanation: ANSWER: (C) IleumREF: Ganong, 22nd edition, p471Bile salts and vitamin B12 are mainly absorbed by ileumIron and vitamins (other than B12) are absorbed mainly from proximal small intestine (duodenum and jejunum)Maximum fat absorption- JejunumLong chain fatty acid absorption- Duodenum+ JejunumShort chain fatty acid- Colon