For Which of These Reasons Would a Nurse Researcher Choose

For which of these reasons would a nurse researcher choose to assign participants randomly to groups in a study?

A) To help ensure that all groups within a study are representative of the larger population
B) To increase the chance that the study groups will be different from each other with regard to extraneous variables
C) To help ensure that current events do not influence the outcomes of the study
D) To eliminate the need for establishing specific study criteria and participant eligibility