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: Social & Preventive Medicine
Iodised oil ( usual dose of 1 ml i/m) gives protection for 
Select and explain. 
A. 3-4 years, B. 3-4 months, C. 3-4 weeks, D. 10-12 years
A: 3-4 years
Answer: A: 3-4 years 
Explanation: Intramuscular Iodised Oil (poppy-seed oil): Average dose 1 ml injection provided protection for 4 years
Oral Iodised Oil: 2 ml dose is effective for 2 years