Which of the following statements is/are incorrect?
a) In the absence of water, the kangaroo rat in North American deserts is incapable of meeting its entire water requirement.
b) In the kangoroo rat, internal fat oxidation occurs in which water is a by-product. 
c) Kangaroo rats cannot survive in the absence of an external source of water.
d) Small animals are mostly found in the polar regions.
Select the correct option.