A history professor wanted to know whether students do better when an exam is open-book versus closed book. He allowed one section of his class to take the exam open-book while a second section of the class took the exam closed-book. He used the exam grade as a measure of how well the students did on the test. What type of statistic would you use to analyze the data? O A paired t test A one-way ANOVA A between subjects t test O A two-way ANOVA