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 total of 3500 patient with thyroid cancer are identified and surveyed by patient interviews with reference to past exposure to radiation. The study design most appropriately illustrates - 
Select and explain. 
A. Case series report, B. Case control study, C. Case report, D. Clinical trial
A: Case series report
Answer: A: Case series report 
Explanation: None