Sea level is measured over a 20 year period. The graph shows the number of years since the study began and the corresponding change in sea level. Which statement best describes the rate of change for the situation?
A. The height of the water increases 0.3 cm per year.
B. The height of the water increases 1.5 cm per year.
C. The height of the water increases 2 cm per year.
D. The height of the water increases 6 cm per year.