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.
You don’t have any options so idk
Answer:
Liquid metal.
Tell me if wrong. :) Hope it helps!
Explanation:
Will occur spontaneously without the need of an activator because they have a great internal energy