Genetic diversity is the total number of species with different genetic characteristics. These are the source of biodiversity and variation. Tropical South America has the highest plant diversity of any region today, but this richness is usually characterized as a geologically recent development (Neogene or Pleistocene). From caldera-lake beds exposed at Laguna del Hunco in Patagonia, Argentina, paleolatitude approximately 47 degrees, we report 102 leaf species. So, the correct answer is option D.