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 case control study is not characterized by ? 
Select and explain. 
A. Cases with the disease are compared to controls without the disease, B. Assessment of past exposure may be biased, C. Definition of cases may be difficult, D. Incidence rates may be computed directly
D: Incidence rates may be computed directly
Answer: D: Incidence rates may be computed directly 
Explanation: Ans. is 'd' i.e., Incidence rates may be computed directly