Final answer:
The limiting factor in a population of organisms is genetic diversity.
Step-by-step explanation:
The limiting factor in a population of organisms is d) Genetic diversity.
Limiting factors are factors in the environment that can lower the population growth rate. They can include a low food supply, lack of space, competition for limited resources, and more. However, genetic diversity is not considered a limiting factor because it refers to the variation of traits among individuals in a population. Genetic diversity actually helps a population thrive and adapt to changing environments.