Students in Statistics Classes Were Asked Whether They Preferred a 10-Minute

Multiple Choice

Students in statistics classes were asked whether they preferred a 10-minute break or to allow them go out of class 10 minutes early. In a sample of 150 students, 40 preferred a 10-minute break, 80 preferred going out 10 minutes early, and 30 had no preference. We want to determine if there is a difference in students' preferences. The mean and the standard deviation, respectively, of the sampling distribution of the number of students who preferred going out early are

A) 50 and 30.
B) 60 and 30.
C) 50 and 5.477.
D) 60 and 5.477.