The correct answer is option 1, Western Ghats.

The Western Ghats is a mountain range that runs along the western coast of India. It is internationally recognized as a biodiversity hotspot, which means it is an area with a high level of species diversity and a large number of endemic species.

The Western Ghats is home to a wide range of ecosystems, including tropical rainforests, grasslands, and moist deciduous forests. It is known for its rich flora and fauna, with thousands of plant and animal species, many of which are found nowhere else in the world. Some iconic species found in the Western Ghats include the Indian elephant, Bengal tiger, and Lion-tailed macaque.

This region plays an important role in maintaining ecological balance and providing various ecosystem services, such as water regulation, carbon sequestration, and soil conservation. It is also a major source of livelihood for local communities through agriculture, forestry, and tourism.

While the other options (Western Himalayas, Eastern Ghats, and Northern Himalayas) are also important regions in terms of biodiversity, the Western Ghats has been specifically recognized as a global biodiversity hotspot.