The correct option is C Allens Rule
A. Jordan's rule- states that, inverse relationship between water temperature and meristic characteristics in various species of fish.
B. Bergmann's rule- states that, species of larger size are found in colder environments, and species of smaller size are found in warmer regions.
C. Allen's Rule- states that,body form such as the limbs, ears, and other appendages of the animals living in cold climates tend to be shorter than in animals of the same species living in warm climates.
D. Gloger's rule- states that, birds and mammals should be darker in humid and warm environments compared to colder envioronment.
( Thus the correct answer is Option-C .Allen's Rule )