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
[{'content': 'The study which proceeds from cause to effect \nSelect and explain. \nA. Retrospective, B. Case control, C. Cohort, D. Descriptive', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]