Researchers investigated the physiological changes that accompany laughter. Ninety subjects (18-34 years old) watched film clips designed to evoke laughter. During the laughing period, the researchers measured the heart rate (beats minute) of each subject, with the following summary results: x = 73.9, s = 6. It is well known that the mean resting heart rate of adults is 71 beats per minute. Complete parts a through d below. a. Set up Ho and He for testing whether the true mean heart rate during laughter exceeds 71 beats per minute. Choose the correct answer below. O A. Ho: H =71 O B. Ho: = 71 He: H = 71 He: 71 b. If a = 0.10, find the rejection region for the test. Choose the correct answer below. O A. z > 1.28 or z 1.28 O C. z 1.645 O E. Z 1.645 or z