The correct answers are options 'A, B, and D'. Let's discuss each of these options in detail:

a) The carrying capacity acts as a moderating force in the growth rate of the population:
The carrying capacity refers to the maximum number of individuals that a particular environment can sustainably support. In a logistic growth model, as the population size approaches the carrying capacity, the growth rate slows down. This is because resources become limited, leading to increased competition for resources and reduced reproductive success. The carrying capacity acts as a limiting factor, preventing the population from continuously growing at an exponential rate and stabilizing it at a certain size.

b) Intraspecific competition occurs:
Intraspecific competition refers to competition for resources among individuals of the same species. As the population size increases, the availability of resources such as food, water, and shelter becomes limited. This leads to increased competition among individuals, which can result in reduced reproductive success, increased mortality rates, and overall slower population growth. Intraspecific competition is a key factor in the logistic growth model and plays a significant role in regulating population size.

c) Per capita growth rate stays the same regardless of population size:
This statement is incorrect. In the logistic growth model, the per capita growth rate (the rate of increase in population size per individual) decreases as the population approaches the carrying capacity. Initially, when the population size is small, the per capita growth rate is high as resources are abundant and competition is low. However, as the population size increases and resources become limited, the per capita growth rate decreases. This is because individuals have to invest more energy in competing for resources, which reduces the energy available for reproduction. Therefore, the per capita growth rate is not constant but rather decreases as the population size approaches the carrying capacity.

d) If the individuals are few, then exponential growth occurs:
This statement is correct. In the logistic growth model, when the population size is small relative to the carrying capacity, the population can exhibit exponential growth. In this phase, resources are abundant, and there is little to no competition, allowing individuals to reproduce at their maximum potential. However, as the population approaches the carrying capacity, the growth rate slows down, and the population enters the logistic growth phase, where the growth rate is moderated by the carrying capacity and intraspecific competition.

Overall, the logistic growth model takes into account the carrying capacity, intraspecific competition, and the effect of population size on the growth rate. It provides a more realistic representation of population growth compared to the simplistic exponential growth model.