Explanation:

- Tsomgo Lake, also known as Changu Lake, is a high-altitude lake.

- It is located in the Indian state of Sikkim.

- Nestled at an altitude of about 3,753 meters, it is a glacial lake.

- The lake is a popular tourist destination due to its scenic beauty.

- Option 1: Nagaland

- Does not have Tsomgo Lake.

- Known for its rich cultural heritage and flora and fauna.

- Option 2: Arunachal Pradesh

- Located in the northeastern part of India.

- Famous for its natural beauty but does not house Tsomgo Lake.

- Option 3: Sikkim

- Correct answer.

- Tsomgo Lake is a significant tourist spot here.

- Option 4: Mizoram

- Known for its rolling hills and valleys.

- Tsomgo Lake is not located here.