<prompt> Selection bais is due to -Procedure used to select subjectsFactors that influence study participationDue to people curiocity about goalsDue to mixing of effects  <response>: Ans is a i.e., Procedure used to select subjects b i.e., Factors that influence study participation Bias Selection biases are distortion that result from procedure used to select subjects and from factors that influence study participation. Groups to be compared are differentially susceptible to the outcome even before the experimental maneuver is performed. Selection bias may be of following typesi Surveillance!detection bias It results from the use of a particular diagnostic technique or type of equipment.ii Neyman survival bias incidence-prevalence bias This type of bias is due to missing of fatal cases, mild cases or cases of shorter duration from the study.iii Referrel bias volunteer bias Volunteer or referral bias occurs because people who volunteer to participate in a study or who are referred to it are often different than non-volunteersnon referrel. This bias usually favors the treatment group, as volunteers tend to be more motivated and concerned about there health.iv Response bias This type of bias occurs when those who respond to a survey differ in important ways from who do not respond.v Berkesonian bias Berksonian bias results from the greater probability of hospital admission for people with two or more disease than for people with one disease. So, it is also known as admission rate bias. 