This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
Best test to detect iron deficiency in community is - 
Select and explain. 
A. Transferrin, B. Serum ferritin, C. Serum iron, D. Hemoglobin
B: Serum ferritin
Answer: B: Serum ferritin 
Explanation: The single most sensitive tool for evaluating the iron status is by measurement of serum ferritin. REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICAL 21ST EDITION. PAGE NO - 623