The dot plots represent the number of students who enrolled each year for the AP psychology course at two schools. The data represents the last 24 years. Which statement is true based on the mean number of students enrolled in the course?

A number line for school 1 from 14 to 26. Here 14 has one dot, four dots at 16, three dots at 17, two dots at 18, four dots at 20, three dots at 21, two dots at 22, two dots at 23, one dot at 24, and two dots at 25. 

A.
The variability in the number of students enrolled each year in school 1 is equal to the variability in the number of students enrolled in school 2.
B.
The variability in the number of students enrolled each year in school 1 is generally lower than the variability in the number of students enrolled in school 2.
C.
The number of students enrolled each year in school 1 is generally higher than the number of students enrolled in school 2.
D.
The number of students enrolled each year in school 1 is generally lower than the number of students enrolled in school 2.