<prompt> Which of the following is ideal to ensure similarity between experimental control groupsRandomizationStratified randomizationMatchingCross over study  <response>: Stratified randomization: Study population is first stratified by each variable which is considered important, and then randomization is done to each treatment groups within each stratum.- Comparison groups become similar as possible as regards participant characteristics that might influence the response to the intervention- Equal numbers of participants with a characteristic thought to affect prognosis or response to the intervention will be allocated to each comparison group.- Stratification increase the likelihood that two groups will be more comparable. 