This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
A patient Secta is diagnosed to be having iron deficiency anemia. The agent that can be used to improve the absorption of iron is: 
Select and explain. 
A. Antacids, B. Tetracyclines, C. Phosphates, D. Ascorbic acid
D: Ascorbic acid
Answer: D: Ascorbic acid 
Explanation: (Ref: KDT 6/e p582, 583) Substances improving the absorption of iron Substances improving the absorption of iron 1. Acid 1. Antacids 2. Reducing substances like ascorbic acid 2. Phosphates 3. Meat 3. Phytates 4. Tetracyclines 5. Food in the stomach