This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Descriptive Epidemiology, Subject name: Social & Preventive Medicine
Incidence is calculated by - 
Select and explain. 
A. Cross sectional study, B. Cohort study, C. Case control study, D. None
B: Cohort study
Answer: B: Cohort study 
Explanation: Ans. is 'b' i.e., Cohort study CharacteristicsCohort StudyCase control StudyCross Sectional StudyDesignProspectiveRetrospectiveOne point in timeIncidenceEstimatedNot estimatedNot estimatedPrevalenceNot estimatedNot estimatedEstimatedCalculationso Incidence rateso Relative risko Attributable risko Odds ratio