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
People living in developing countries - 
Select and explain. 
A. 90%, B. 80%, C. 70%, D. 60%
B: 80%
Answer: B: 80% 
Explanation: About three fourths of world's population lives in the developing countries.
95% of growth of population is occurring in developing countries.
China is most populous country in the world.
India is 2nd most populous country in the world (17.5% of world's population).