The most plausible hypothesis to explain why species richness is higher in tropical than in temperate regions is that
A) tropical communities are younger.
B) tropical regions generally have more available water and higher levels of solar radiation.
C) higher temperatures cause more rapid speciation.
D) diversity increases as evapotranspiration decreases.
E) tropical regions have very high rates of immigration and very low rates of extinction.
Answer: B - tropical regions genreally have more available water and higher levels of solar radiation