This question tests knowledge of historical and administrative facts about northeastern Indian states.

✅ Pair I: Arunachal Pradesh – Correct

• Itanagar, the capital, is named after Ita Fort.
• The state has two National Parks: Namdapha and Mouling.

✅ Pair II: Nagaland – Correct

• Nagaland attained statehood via a constitutional amendment and came into being on 1 December 1963 through the State of Nagaland Act, 1962.

✅ Pair III: Tripura – Correct

• Tripura was a Part 'C' state, became a Union Territory in 1956, and was granted statehood in 1972.