Ecologists are the persons who study the interrelationships between organisms and their environments. Like they research upon the species found in forests or deserts interact with each other and as well as their surroundings.
They test whether a species is occupying its complete fundamental niche or only a portion of it by observing if the species are expanding their range after the removal of a competitor because two species with the same fundamental niche will exclude other competing species.
The answer to your outstanding question is 3
Are there any answer choices, I can’t see very clearly
