The x-axis represents elevation (meters), and the y-axis represents the measure of plant diversity.
The quadratic function graphed above models a particular measure of plant diversity as a function of the elevation in a region of Switzerland. Based on the model, as the elevation increases from 1,500 meters to 2,500 meters, what happens to the measure of plant diversity?
It increases steadily.
It decreases steadily.
It increases then decreases.
It decreases then increases.
