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
A coho study is - 
Select and explain. 
A. An analytical study, B. A descriptive study, C. A corelational trail, D. An experimental study
A: An analytical study
Answer: A: An analytical study 
Explanation: Coho study is also known as incidence study. The cohos are identified prior to the appearance of disease under investigation. The study group so defined are observed over a period of time to determine the frequency of disease among them Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 83