Dr Hopkins Is About to Conduct a Study in Which

Dr. Hopkins is about to conduct a study in which he will present several different lists of words to subjects to memorize Some lists are long and some are short. Dr. Hopkins plans to present all the short lists before presenting the long lists. Worried that the order in which the lists are presented to subjects may affect the outcome of the study, you advise Dr. Hopkins to

A) assign subjects randomly to groups.
B) counterbalance the presentation of the lists.
C) use a pretest to make sure all subjects have about the same memory abilities.
D) make sure that all the words in the lists are unfamiliar to subjects to reduce the possibility of bias.
E) make sure all of the lists are the same length.