Which of the following statements best represents the productivity hypothesis regarding species richness?
a. The larger the area, the greater the number of species that will be
found there.
b. Temperate regions have a lower species richness due to the lack of
time available for migration after the last Ice Age.
c. The number of species in a particular community is directly related
to the amount of available energy.
d. As invertebrate productivity increases, species richness will increase.