We reject the options a) and b) since the question says that the data supports "equally" both cases - so we have no basis for making a choice either way.
Further, in science the decisions are reached based on facts, not voting, so we also reject the answer D .
We are left with the answer C and this is also the best practice in science - when unsure, leave it as a hypothesis.
Traits such as skin color and height are variable throughout the human population because these traits are controlled by more than one cell. The cells don't perform at the same rate and don't produce the same biomolecules. Therefore, the maximum height of a person is not achieved which results to variations.
The only reasonable answer I can see is
D. Ectothermic animals need the warmth before they can move around to hunt food.
