D. fingernails
Skin, hair, and vertebrae are all the outer layer of the body and protect the body. The fingernails aren't part of that.
Answer:
The correct answer is convergent evolution.
Explanation:
The wings of bats, butterflies, and most birds are the example of analogous structure. Analogous structures are the structures which are similar in appearance and function but have separate evolutionary origin.
They are similar superficially because they experienced a natural selection that evolved them to have that shape which helps them to fly. Analogous structures are produced due to convergent evolution.
Convergent evolution describes the presence of the same trait in unrelated species. Therefore the correct answer is convergent evolution.
I believe the answer you're looking for is:
Condensation- If the air cools, then water vapor molecules slow down and some can not remain a vapor. They cluster in the air to form tiny liquid droplets. This is called condensation. In clouds, the liquid droplets formed by condensation are small and light enough that they stay in the air.
<em>hope this helps! :)</em>