The correct option is (d).
Explanation
Under Article 231 of the Constitution of India, the Parliament has the power to establish a common High Court for two or more States or for two or more States and a Union Territory. The Guwahati High Court serves as a prominent example of a common High Court exercising territorial jurisdiction over multiple states in the North-Eastern region.
Analysis of Jurisdiction
Originally, the Guwahati High Court had jurisdiction over the seven North-Eastern states (often referred to as the "Seven Sisters"). However, following the North-Eastern Areas (Reorganisation) and Other Related Laws (Amendment) Act, 2012, separate High Courts were established for the states of Manipur, Meghalaya, and Tripura in March 2013.
Consequently, the territorial jurisdiction of the Guwahati High Court currently extends to the following four states:
- Assam (Principal Seat at Guwahati)
- Nagaland (Bench at Kohima)
- Mizoram (Bench at Aizawl)
- Arunachal Pradesh (Bench at Itanagar)
Therefore, all the states listed in the question (Assam, Nagaland, Mizoram, and Arunachal Pradesh) share the common High Court at Guwahati.
Key Takeaway: The Guwahati High Court has the largest jurisdiction in terms of the number of states (four: Assam, Nagaland, Mizoram, Arunachal Pradesh). Manipur, Meghalaya, and Tripura have their own separate High Courts.