The answer would be D. Tropical Rainforest, this would be due to the abundance of rain which creates plenty of vegetation and then, more herbivores will live in the rainforest, and the more herbivores there are, the more carnivores will come to the rainforest. The canopy of the tall trees also provide shelter for countless of thousands of species of birds.
The theory is the Continental drift, the super-continent is called the Pangaea.
