The correct answer is Option 2: 1 and 2 only.

1. Eastern Himalayas:

The Eastern Himalayas is indeed a Biodiversity Hotspot. It is considered one of the most biologically diverse regions on the planet. This region spans across Bhutan, northeastern India, Nepal, and parts of southern Tibet. It is home to a wide range of habitats, including alpine meadows, subtropical forests, and high-altitude glaciers. The Eastern Himalayas house numerous endemic and endangered species, such as the Bengal tiger, Asian elephant, red panda, and several species of primates. The region`s rich biodiversity is a result of its unique geographic location, complex topography, and climatic variations.

2. Eastern Mediterranean region:

The Eastern Mediterranean region is another Biodiversity Hotspot. This region includes countries like Cyprus, Greece, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey. It encompasses a diverse range of ecosystems, including forests, wetlands, coastal areas, and Mediterranean scrublands. The Eastern Mediterranean region is known for its high levels of plant endemism, with many plant species found nowhere else in the world. It is also an important migratory corridor for birds, providing crucial stopover points during their annual migrations. The region faces several conservation challenges, including habitat loss, overexploitation, and invasive species, making it a priority for biodiversity conservation efforts.

3. North-western Australia:

Contrary to Options 3 and 4, the North-western Australia region is not considered a Biodiversity Hotspot. While it does have unique ecosystems and supports diverse flora and fauna, it does not meet the criteria for a designated hotspot. Biodiversity Hotspots, as defined by Conservation International, are specific areas characterized by exceptional levels of species richness and high levels of endemism, coupled with significant habitat loss. While North-western Australia has unique biodiversity, it does not meet the specific criteria to be classified as a Biodiversity Hotspot.

In summary, the Eastern Himalayas (Option 1) and the Eastern Mediterranean region (Option 2) are recognized as Biodiversity Hotspots due to their exceptional levels of species richness, high levels of endemism, and significant conservation importance. North-western Australia (Option 3) does not fulfill the criteria to be considered a Biodiversity Hotspot.