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
[{'content': 'In a randomized controlled trial, the essential purpose of randomization is- \nSelect and explain. \nA. To produce double blinding, B. To decrease the follow - up period, C. To eliminate the selection bias, D. To decrease the sample size', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Randomization ensures that the investigator has no control over the allocation of paicipants to either study or control groups, thus eliminating what is known as selection bias. In other words by random allocation, every individual gets an equal chance of being allocated into either group or any of the trial groups ( refer pgno:82 park 23rd edition)', 'role': 'assistant'}]