I would go with B & D because they change over time and they can go extinct like those big octopus in the oceans, they are rare to see in my opinion because they can blend in with other things that keeps them away from danger.
Answer:
The answer to your question is:
Explanation:
1 or more double bonds unsaturated
Usually solid at room temperature saturated
Molecules are tightly packed togheter saturated
Usually liquid at room temperature unsaturated
Most plant fats unsaturated
Most animal fats saturated
Octopus are invertebrates
I think B because Testosterone happen near the tests