The vertebrate endoskeleton is internal while an arthropod's exoskeleton is not
Answer:
A
Explanation:
A, the guy with 1 star provided the most noneducational response I've ever seen.
It turns out that many materials can be solid at a higher temperature if the pressure is also higher. so even though it is hotter in the inner core the pressure in the core is also higher and you can have a solid iron nickel instead of liquid
