A study that is praised for high internal validity would include which of the following elements? A. The subjects are randomly assigned and the only difference between conditions is that the researcher improvises everything in the moment. B. The subjects are randomly assigned and the only difference between conditions is planned, controlled, and carried out consistently by the researcher. C. The subjects are randomly found through a "snowball sampling" technique. D. The subjects are not interacted with by the researcher and must be viewed from a one-way looking glass with the researcher on one side and the subject being viewed by the researcher on the other side