I believe the answer is C. They are a type of jelly fish.
Ans: C- species specialization
Well the number of volcanoes in the pacific ocean are greater because of the ring of fire. Basically what that is is its a hot spot for volcanoes. There's many located under the water there. Its located in the pacific ocean off the coast of California. I haven't heard of any active volcanoes in the Atlantic. That's all the information I can give. I know this probably doesn't help, sorry.
If i'm not mistaken, it's the aorta
White blood cell classification