Social & Preventive Medicine In a controlled trial to compare two treatments, the main purpose of randomization is to ensure that – A The two groups will be similar in prognostic factors B The clinician does not know which treatment the subjects will receive C The sample may be referred to a known population D The clinician can predict in advance which treatment the subjects will receive 💡 Explanation In a controlled trial to compare two treatments, the main purpose of randomization is to ensure that - ✓ Correct Answer: A. The two groups will be similar in prognostic factors