Which type of rock forms when molten material cools and hardens inside earth?
an igneous rock
an extrusive rock
a rock with fine texture
a rock with small crystals

Igneous rock

Explanation:

The answer is An igneous rock

Explanation:

Igneous rocks are those that form when magma (molten rock) cools and solidifies. If cooling occurs slowly below the surface, rocks with large crystals called plutonic or intrusive rocks are formed; Where magma, surrounded by pre-existing rocks, cools slowly, allowing minerals to form large crystals, visible to the naked eye.

the reason the two sea urchins don't compete with each other for food, resources, etc. is because the urchins have adapted to the environment but they have also adapted to each other. this is most likely because the genes of the sea urchins.