This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
What is the formula for parenteral iron therapy : 
Select and explain. 
A. 4.4. X body weight (kg) X Hb deficit (g/dl), B. 3.3. X body weight (kg) X Hb deficit (g/ dl), C. 2.2 X body weight (kg) X Hb deficit (g/dl), D. 1.1 X body weight (kg) X Hb deficit (g/dl)
A: 4.4. X body weight (kg) X Hb deficit (g/dl)
Answer: A: 4.4. X body weight (kg) X Hb deficit (g/dl) 
Explanation: None