Explanation:

- Pakyong Airport is located in the state of Sikkim.

- It is one of the highest airports in India, offering stunning views of the surrounding Himalayas.

- Option 1: Sikkim ??

- The correct answer. The airport is situated in Pakyong, Sikkim.

- Option 2: Assam

- Assam is another northeastern state, but it does not have the Pakyong Airport.

- Option 3: Arunachal Pradesh

- Arunachal Pradesh is nearby, but the airport is not located there.

- Option 4: Nagaland

- This state is in the northeastern region too, but without Pakyong Airport.

- Option 5: None of the above

- Since the correct option is provided, this is incorrect.