Answer: A. resources become scare
Exponential population growth is the phenomena in which number of individuals increase in a population at a constant rate. Logistic population growth occurs when the growth rate decreases as the population reaches the carrying capacity. Carrying capacity is the maximum number of individuals of a population an ecosystem can support in terms of availability of resources (food, shelter). The exponentially growing musk rat population will deplete in number in order to reach the carrying capacity of the ecosystem. The exponential growth will change to logistic growth due to scarcity of resources.