In the sentence "The driest area in the world is a desert in Chile," the adjective words are "driest" and "Chilean". "Driest" describes the degree of dryness of the area and "Chilean" specifies the location of the desert. However, in the given sentence, "Chilean" is not an adjective, it should be "Chile." So the correct answer is "driest."
*IG:whis.sama_ent*