If our eyes were sensitive only to x rays the world would appear dark because X-ray light does not reach Earth's surface.
I think the correct answer from the choices listed above is option C. The continent that was not covered by ice during the Pleistocene ice age. This is because the southern location of this nation made it much harder for ice to form, even during this time. Hope this answers the question.
Ananabjajanajajjaananjajananannansnan