This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiological Study, Subject name: Social & Preventive Medicine
Cross sectional study is associated with: 
Select and explain. 
A. Indicates prevalence, B. Incidence, C. Positive predictive value, D. Relative risk
A: Indicates prevalence
Answer: A: Indicates prevalence 
Explanation: Ans. (a) Indicates prevalenceRef : K. Park 23rd ed. / 75-77Cross sectional study is the simplest form of observational epidemiological study which is based on single examination of a cross section of a population at one point of time, results of sample are then projected to the whole populationAdvantages* Provides prevalence of a disease* Provides a whole picture of population at one point of time* More useful for chronic diseaseDisadvantages* Tells about distribution of a disease rather than the etiology* Establishment of time sequence of a disease is not possible* Provides little information of a natural history and incidence of a disease