Endemism, Hotspots and Megadiversity

Three of the following criteria have contributed to the recognition of Western Ghats-Sri Lanka and Indo-Burma regions as hotspots of biodiversity: 1. Species richness 2. Vegetation density 3. Endemism 4. Ethno-botanical importance 5. Threat perception 6. Adaptation of flora and fauna to warm and humid conditions Which three of the above are correct criteria in this context?