If volcanic rock is found far inland within a continent, what is one possible reason why it is there?

What does the law of increasing costs say? a. as you make more and more of one good or service, you will also make more and more of another. b.as you make less and less of one good or service, you will also make less and less another. c.as you make more and more of one good or service, you will make less and less of another. d.there is no change in production levels when you shift from one good or service to another