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: Dental
An epidemiological investigation undertaken to test the hypothesis regarding the causation of a disease is called 
Select and explain. 
A. Case control study, B. Cohort study, C. Prospective study, D. Descriptive study
A: Case control study
Answer: A: Case control study 
Explanation: None