The answer is B.
This is because it says that the population tends to level off meaning that it stays around the same population size since it is the maximum amount of individuals that can survive.
The reticular activating system's main function is regulating arousal and sleep−wake transitions
<span>Scientific models are only as good as the data that goes into them. When the data is incomplete or inaccurate, the model doesn't give a true picture.
Sometimes we miss an important part of the picture. We just don't understand all the factors that affect the situation, so there are factors that aren't even programmed into the model. </span>
It was probably because when a area had too much pollution, they could easily migrate away somewhere else by flying, while humans have to stay everywhere. Another reason could've been that birds can adapt to places quicker than other animals.
Hope it helps!
