Researchers recruited over 1,000 patients with chronic back pain to participate in a study about the benefits of acupuncture. Each subject was randomly assigned to one of these treatment plans: traditional Chinese acupuncture, placebo acupuncture, and conventional pain treatment (medication and physical therapy). What is the primary purpose of randomly assigning subjects to different treatment plans? Group of answer choices It is to ensure that both the subjects and researchers are blind to who is in which group. It is to take care of the effects of the lurking variables so that the main difference between the groups is only due to the treatments. It is to have a representative sample of patients with chronic back pain. It is to generalize the findings to the population at large