57. Nora is interested in differences in amount of content retained from a lecture based on time of class. She compares her two sections--one that meets at 8 am and one that meets at 2 pm- by testing them, unannounced, on content that she taught two weeks ago. Which of the following designs is Nora best illustrating? a. One shot case study b. One group pretest-posttest design c. Posttest only control group design (1. Static group comparison