Which of the following is not a megadiverse country - one that harbors a high number of the earth's endemic species?

Thailand is not considered a megadiverse country because it does not harbor a high number of the Earth's endemic species. Megadiverse countries are typically characterized by a large concentration of plant and animal species that are found exclusively within their borders. While Thailand does have a diverse range of wildlife and ecosystems, it is not among the countries with the highest levels of endemism. Other countries like Brazil, Colombia, Indonesia, and Australia are known for their incredible biodiversity and are often referred to as megadiverse countries.