This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2019, Subject name: Pathology
Iron entry into enterocytes occurs which of the following? 
Select and explain. 
A. DMT-1, B. Ferropoin, C. Transferrin, D. Hepcidin
A: DMT-1
Answer: A: DMT-1 
Explanation: GI Luminal non-heme iron is mostly in the Fe3+ (ferric) state and must first be reduced to Fe2+ ferrous) iron by ferrireductases, such as b cytochromes and STEAP3. Fe2+ iron is then transpoed across the apical membrane of enterocytes by divalent metal transpoer-1 (DMT1).