I think Tibet is the most tropical
What are you asking by this?
The land area of Australia is about the same size as the land area of the continental United States. The correct option among all the options given in the question is option "D". Australia is the sixth largest country in the world in respect to its size. Russia, Canada, Brazil, USA and China have a larger area than the continent of Australia.
I'm not so good at science but I believe just from the Internet and common sense that it could be found in Hawaii, Yellowstone, Iceland, and (not completely sure for last one) but maybe Pompeii. I know the first 3 are most likely correct but I'm not completely sure about Pompeii. Just look it up, lol