Small animals have a larger surface area relative to their volume,so they tend to lose body heat very fast when it is cold outside. Then they have to expend much energy to generate body heat through metabolism. This is the main reason why very small animals are rarely found in polar regions. Which of the following explains why small animals are more easily able to climb up a rock compared to large animals?

• A
  Small animals have a higher metabolic rate.
• B
  Small animals have a lower oxygen requirement rate.
• C
  Large animals have less muscle capacity compared to small animals.
• D
  It is easier to carry the weight of a small body.