This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
Which of the following required for iron absorption is synthesized in liver and transpoed to intestine by secretion through bile? 
Select and explain. 
A. Apoferitin, B. Apotransferrin, C. Tansferin, D. All of the above
B: Apotransferrin
Answer: B: Apotransferrin 
Explanation: The liver secretes moderate amounts of apotransferrin into the bile, which flows through the bile duct into the duodenum .Here, the apotransferrin binds with free iron and also with ceain iron compounds, such as hemoglobin and myoglobin from meat, two of the most impoant sources of iron in the dietRef: Guyton and Hall Textbook of Medical Physiology (12th Edn) page No: 795