Final answer:
Graph B demonstrates logistic growth, ultimately showing that the population has reached its carrying capacity. The S-shaped curve indicates an initial phase of exponential growth followed by a leveling off as resources become limited.
Step-by-step explanation:
The statement that best describes what has happened to the population in Graph B is that the population has reached its carrying capacity. Graph B illustrates a logistic growth pattern, which is marked by three phases: the initial exponential growth, followed by a decreased growth rate as resources become limited, and finally, the leveling off at the carrying capacity. The carrying capacity is where the population size stabilizes because the environment can no longer support a larger population. This is shown by the S-shaped curve that rises quickly at first but then plateaus as the growth rate balances with the rate of deaths and births in the population.