The first of the two "undeniable facts" is that any localized population of a species has the potential to produce far more offspring than the local environment can support. This fact is important to understanding evolution because it means that ____________.a. there is competition for survival among the individuals of the population b. the population will ultimately overwhelm its environment, causing the environment to collapse c. the species that has the greatest numbers will be able to dominate over other species within its environment d. the population will tend to grow with time

A Habitat can be defined as the physical location on the earth where the individuals (population) of a species live.
Every habitat is known to have its own carrying capacity. This means that the availability of resources in the habitat that is required for sustaining the population of any species is fixed and limited.
When a population of any species grows in a localised habitat it utilises the resources available in the habitat for its growth, metabolism, survival and reproduction.
These processes occur rapidly when the available resources are abundant.
However, when the population of species grows such that it exceeds the carrying capacity of its habitat, that is, the available resources become limited to the growing population, the individuals belonging to the particular species tend to compete with each other for the available resource, hence there is an intra-species competition that develops.
In this competition, the best adapted individuals of the species survive while the least adapted ones perish thereby reducing the population size.