The answer would be: <u>Molten material that cooled quickly.</u>
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.
Geologist Alfred Wegner noticed similar rocks & fossils remains were found on Continents which seemed to fit together. He called saw that it was the result of Continental drift and Pangea. Some evidence of the Drift was Rock evidence- Mountain ranges, Glacial scares, Location of coal deposits, ETC..
People couldn't image how the Earth could be millions of years ago. But the 1960's evidence would prove Continental Drift is TRUE and .. the story continues (as all good science!)
Continental drift means that continents move away from each other or separated.
Answer:
Decrease in supply, increase in price
Decrease in price, increase in supply