9. In a hypothetical study, let's assume that an aviation safety officer conducted a na- tionwide survey of flight schools and reported that approximately 4% of the flight schools' training fleet had a defective magneto. Let's further assume that the safety officer randomly selected two samples of aircraft across the United States and tested for the defective component. Sample A had 150 planes and Sample B had 250 planes. Which of the following statements is true?

a. MA MB C. SEA SEB