This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Levels of Prevention of Disease, Subject name: Social & Preventive Medicine
The most cost-effective mode of intervention for prevention of disease is: 
Select and explain. 
A. Health education, B. Environmental modifications, C. Nutritional interventions, D. Lifestyle and behavioral changes
A: Health education
Answer: A: Health education 
Explanation: Health education is one of the most cost- effective interventions. A large number of diseases could be prevented if people were adequately informed & if they were encouraged to take necessary precautions in time.