I think the correct answer from the choices listed above is option A. The anatomical adaptation which helps an elephant regulate its body temperature are its large ears increase surface area so that more heat is lost by radiation. Heat can be released as they flap these ears. So there is your correct answer
The example that does not exhibit sexual selection is:
D. male elephant seals fighting over territory and potential female mates
The competition for territory is also one that helps the elephant seals survive. This is because a seal with a larger territory is likely to have access to a greater amount of resources, ensuring its survival.
Any characteristic, whether a physical trait, a behaviour, a physiological adaptation etc can make an organism more or less likely to survive in a particular environment.
A dark colour could help a rabbit survive if it lives in a dark forest, because predators can't see it so well, but it would be less likely to survive in the arctic, where the environment is all white and it would show up.
In terms of the characteristics, think about: does it help the organism get food? Does it help protect the organism from predators? If it does, that organism is more likely to survive, and pass the characteristic on to it's offspring. If a bacterium has a characteristic of not being killed by antibiotics, this will help it to survive and breed.
Answer:
Atp, because it literally Powers the cell.
