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
A 50-year-old obese man with hyperlipidemia, hypertension, and type 2 diabetes mellitus comes to the physician for a routine examination During the visit he asks, “What is my risk of having a heart attack?” 

While searching your information database, which of the following represents the best study design to address his question? 
Select and explain. 
A. Case-control study, B. Case series, C. Cohort study, D. Cross-sectional study
C: Cohort study
Answer: C: Cohort study 
Explanation: None