An igneous rock is found on the ground and has no identifiable crystals. What is the most likely origin of this rock? molten material that cooled slowlymolten material that cooled quicklyrock that was eroded by surrounding rocksrock that was exposed to extreme pressure

The answer would be: Molten material that cooled quickly.

Igneous rocks are formed by the cooling of molten material. So we can cross out the last two choices. The rock has no identifiable crystals so it is most likely an Extrusive igneous rock. They form on the surface where they cool quickly.

Those that form underground are called intrusive rocks. They cool slowly allowing enough time for crystal formation.