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
Type of sampling, if random sample is taken from a characteristic population, eg. Hindus, Muslims, Christians etc- 
Select and explain. 
A. Simple random, B. Systemic random, C. Stratified random, D. Cluster
C: Stratified random
Answer: C: Stratified random 
Explanation: Ans. is 'c' i.e., Stratified random "Stratified random sampling is paicularly useful where one is interested in analysing the data by a ceain characteristic of the population, viz Hindus, Muslims, Christians, age group etc, - as we know these groups are not equally distributed in the population." ............ Park