The answer is D, for when one tropic level is eaten by the tropic level above it, the tropic level is supporting the higher one. I. E. Rabbits are supported by the grass because rabbits eat the grass. Also, the grass population would be larger than rabbits, the rabbits larger than snakes, so on and so forth, so B is ruled out. B states that each population is larger than the one BEFORE it, but there is no way there would be more rabbits than grass. Also, there are both herbivores and carnivores in the food chain, so A and C are out. The best answer is D.
When the upper water layers warm in the summer months, they become separated from deep water by a transition zone known as a thermocline. In a thermocline, the temperature decreases rapidly with small increases in depth. This phenomenon linking temperature change with depth is called temperature stratification.
The correct answer is that it is an organism's habitat and inherited traits that determine its niche.
The principle of competitive exclusion states that the two species cannot hold the similar niche in the same habitat. A niche of an organism is predicted by its habitat that is its physical surrounding. The inherited traits and adaptation enhances the organism's chances of survival, and it also predicts a niche of an organism.