Explanation:

- Option 1: Himachal Pradesh

- Located in northern India, known for its stunning Himalayan landscapes and hill stations. However, it does not host the Asan Conservation Reserve.

- Option 2: Uttarakhand

- Correct Answer

- Established to protect birds and aquatic animals, Asan Conservation Reserve is situated at the confluence of the Asan and Yamuna Rivers in Uttarakhand. It is a popular spot for birdwatching.

- Option 3: Sikkim

- Renowned for its biodiversity and Himalayan scenery, it is home to several sanctuaries but not the Asan Conservation Reserve.

- Option 4: Arunachal Pradesh

- Known for rich cultural diversity and unique wildlife, it hosts several reserves, but Asan is not one of them.