On a certain math exam, 10 \% of the students got 70 points, 25 \% got 80 points, 20 \% got 85 points, 15 \% got 90 points, and the rest got 95 points. What is the difference between the mean and the median score on this exam?
Answer Choices
A. 0
B. 1
C. 2
D. 4
E. 5