This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
Not true about experimental study 
Select and explain. 
A. Always prospective, B. Unethical to use in animal, C. Can not be double blinded in animal trails, D. Interim analysis is permitted
B: Unethical to use in animal
Answer: B: Unethical to use in animal 
Explanation: Experimental epidemiology meant the study of epidemics among colonies of experimental animals such as rats and mice ( refer pg: 80, park 23 rd edition)