What Is One Hypothesis Biologists Have Proposed to Explain Latitudinal

What is one hypothesis biologists have proposed to explain latitudinal gradients in species richness?

A) Intense predation in polar regions limits the number of species.
B) Lack of pathogenic organisms in the tropics promotes species richness.
C) Lack of mutualistic interactions at higher latitudes limits the number of species.
D) Presence of extensive mountain ranges and coastlines at higher latitudes limits species richness.
E) Greater energy flow in the tropics has led to narrower,more specialized niches and thus promoted species diversity.