The 22 students in a health class conducted an experiment in which they each recorded their pulse rates, in beats per minute, before and after completing a light exercise routine. The dot plots below display the results. Beats per minute before exercise Beats per minute after exercise Let and be the standard deviation and range, respectively, of the data before exercise, and let and r1 be the standard deviation and range, respectively, of the data after exercise. Which of the following is true?
A) s1 = s2 and r1 = r2
B) s1 < s2 and r1 < r2
C) s1 > s2 and r1 > r2 D) s1 ≠ s2 and r1 = r2