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 mean study time of students in class b is less than students in class a.
c.) the median study time of students in class b is greater than students in class a.
d.) the range of study time of students in class a is less than students in class b.
e.) the mean and median study time of students in class a and class b is equal.