I did not vote as I feel the choices aren't correct.
You have to look at the purpose of life on Earth. This place was created for Souls to incarnate in a physical body and to experience duality and to learn to in spite of that create a healthy society.
As such humans are highest as it was created for us. Animals come in for other reasons, basically to assist us. And of course they too learn and evolve as they do so.
Dolphins have a very high consciousness and awareness, possibly higher than people. But they too have come here to help us. Their purpose it to bring joy. Not the conditional joy you may feel when you get a compliment or have a nice moment. The unconditional joy which remains regardless, even when you are going through a rougher time. The joy that will then still be there at your core.
Some animals have a seemingly higher purpose than others, like the dolpins, whales, and lions etc., but that is seemingly. In the whole each and everyone is as important as the other. Just that we may feel more affinity with one type, especially our pets of course. But also the concept of totem/power animals is based on this. Sometimes you need the specific energy of an animal, sometimes for a short time, other times for years.

Like we have our origins on another planet or star, so do animals. Cats, lions (all felines) and rabbits for instance come from Orion. That's what makes it such a nice joke that the cat in MiB 1 was called Orion :) Sharks come from Mars. I believe their role has to do with leadership, but don't quote me on that, haha.
That's why I feel the options of the vote aren't really correct as thinking in the old paradigm of hierarchy of animals and humans on our planet is 3D thinking.

Diana Cooper has written a book about this all, an oracle deck, free to watch YouTube clips and webinar on YouTube and so on.
But I also know this info/wisdom from other sources.

All births or forms of life experience are equal.
I feel we haven't unlocked the consciousness of other beings, therefore it exists. They do sentient things. They are conscious, so how are we superior. We are just a chance of nature just as the others are.

As Altair mentions, it comes down to the potential for human development, although I don't think this is anything to do with being lucky. Some animal species may be highly developed, but their potential for further development is restricted by the limitations of the forms they work through. We humans have barely scratched the surface of what it means to have a human body.

And all this is restricted to life within the Earth scheme. Beyond this particular scheme I suspect there are other lives who would consider human consciousness as being relatively low.

Peace.