Jorden is looking at a piecewise function graph of a population (number of individuals) versus the temperature (in degrees Fahrenheit). Which of the following BEST describes a stable population in the graph?
A. a straight line because the population increases as the temperature decreases
B. a straight line because the population is constantly increasing over time
C. a straight line because the population is not increasing or decreasing
D. a straight line because the population decreases as the temperature increases