Explanation:

- Majuli is renowned as the largest river island in the world.

- It's located on the Brahmaputra River.

- This island boasts vibrant culture and rich biodiversity.

- Option 1: Arunachal Pradesh

- Known for its lush landscapes and diverse tribes.

- Not the home of Majuli.

- Option 2: Assam

- Lies in the northeastern part of India.

- Majuli is located here.

- Famous for tea plantations and cultural festivals.

- Option 3: Nagaland

- Known for hills and rich cultures.

- Not associated with river islands like Majuli.

- Option 4: Uttar Pradesh

- Located in northern India.

- Notably different geography; no large river islands like Majuli.