<prompt> Randomization:It brings bias in study group, therefore avoidedIt is the Procedure by which participants are allocated into groups usually called study and control groupIt ensures that investigator has full control over allocation of participants to study or control groupIt is done usually before entering in the study and then consent is taken  <response>: Ans. b It is the Procedure by which participants are allocated into groups usually called study and control groupRef: K. Park 23rd ed. 82, 21st ed. 78 Randomization is heart of a control trial. It is a statistical procedure by which the participants are allocated into groups usually called study and control group. It is an attempt to eliminate bias and allow comparability. By doing this it is ensured that investigator has NO control over allocation of participants to study or control group. THIS REMOVES SELECTION BIAS. RANDOMIZATION is done only after the participant has entered the study, i.e. after having been qualified for the trial and has given his informed consent to participate in the study. 