Allen's Rule States That Mammals from Colder Climates Have Shorter

Allen's rule states that mammals from colder climates have shorter ears and appendages than individuals of the same species from warmer areas.The related Bergman's rule states that mammal body size varies with latitude, with larger body size in populations located closer to the poles and smaller body size in populations located closer to the equator.What can explain both of these rules?

A) Larger bodies can store proportionally more fat as insulation than smaller bodies.
B) Smaller bodies can store proportionally more fat as insulation than larger bodies.
C) Heat loss increases as the surface area to volume ratio of the animal increases.
D) Larger bodies have a proportionally larger surface area, and heat radiation varies with volume.