Final answer:
The savanna cannot support a large number of lions because tertiary consumers require a significant amount of energy from their ecosystem and their prey depends on non-photosynthetic organisms for their energy. So the correct answer is Option D.
Step-by-step explanation:
In many ecosystems, the food chain consists of photosynthetic organisms (plants/phytoplankton), called primary producers, which are consumed by herbivores called primary consumers. Lions are tertiary consumers, which means they consume other carnivores. The reason the savanna cannot support a large number of lions is because tertiary consumers require a significant amount of energy from their ecosystem, and their prey, which are smaller carnivorous animals, depend on non-photosynthetic organisms for their energy.