The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon ?

1. The Himalayan Range is recognized as a global biodiversity hotspot, characterized by high species diversity. 2. Option (B) provides the most appropriate reason for this phenomenon. The Himalayas act as a confluence or transition zone between several major bio-geographical zones, including the Palearctic region to the north and the Indomalayan region to the south. This overlapping of different faunal and floral elements contributes significantly to its rich species diversity. Additionally, the extreme altitudinal gradient creates diverse habitats. 3. Option (A) is partially true as some areas receive high rainfall, but rainfall varies greatly across the range, and it is not the single most important factor explaining the overall diversity compared to the biogeographic junction. 4. Option (C) is incorrect; like most regions, the Himalayas have faced introductions of exotic and invasive species. 5. Option (D) is not entirely accurate, as significant parts of the Himalayas experience considerable human interference.