The concept in question pertains to population dynamics within a given habitat, particularly the movement of individuals of a species. Here are the definitions of the terms involved, which will aid in understanding the correct answer:
Thus, the number of individuals of the same species that have come into a habitat from elsewhere is referred to as Immigration.
The number of individuals of the same species that have come into a habitat is referred to as Immigration.
Additional Context:
Correct Answer: (2) Immigration.