The correct answer is A. Nagaland.
Nagaland is the only state in the Indian union which used to have its own separate state constitution. The Nagaland State Constitution was adopted on 21 December 1963. It was a temporary constitution, and was replaced by the Indian Constitution on 1 December 1969.
The Nagaland State Constitution was based on the Indian Constitution, but it had some unique features. For example, it guaranteed the right to self-determination for the Naga people. It also had a provision for a separate Nagaland National Assembly.
The Nagaland State Constitution was a significant document in the history of Nagaland. It was a symbol of the Naga people’s struggle for self-determination. It also helped to pave the way for the integration of Nagaland into the Indian union.
The other options are incorrect because they do not have their own separate state constitutions.
- Jammu and Kashmir has a special status in the Indian union, and its constitution is based on the Indian Constitution.
- Sikkim was a separate state until 1975, when it was merged with India. It does not have its own separate state constitution.
- Goa was a Portuguese colony until 1961, when it was annexed by India. It does not have its own separate state constitution.