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: 4.4 x body weight (kg) x Hb deficit (g/dl)