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
Cause to progression is seen in all except: 
Select and explain. 
A. Case control study, B. Coho study, C. RCT, D. Ecological study
A: Case control study
Answer: A: Case control study 
Explanation: Case control study