Select the correct answer. Twenty students in class A and 20 students in class B were asked how many hours they took to prepare for an exam. The data sets represent their answers. Class A: {2, 5, 7, 6, 4, 3, 8, 7, 4, 5, 7, 6, 3, 5, 4, 2, 4, 6, 3, 5} Class B: {3, 7, 6, 4, 3, 2, 4, 5, 6, 7, 2, 2, 2, 3, 4, 5, 2, 2, 5, 6} Which statement is true for the data sets? A. The mean study time of students in class A is less than students in class B. B. The range of study time of students in class A is less than students in class B. C. The median study time of students in class B is greater than students in class A. D. The mean study time of students in class B is less than students in class A.