Explanation: India's northeastern region is a complex area with several states sharing borders with neighboring countries. Among these states, Sikkim and Arunachal Pradesh are particularly significant as they share international borders with China.
Sikkim, a small state located in the Himalayan region, borders the Tibet Autonomous Region of China. The border between Sikkim and China is approximately 214 kilometers long. Historically, the Sino-Sikkimese border has been a subject of contention, with the McMahon Line being a significant demarcation line that has been a point of dispute between India and China.
Arunachal Pradesh, another northeastern state, also shares a border with China. The border between Arunachal Pradesh and China is much longer, stretching over 1,126 kilometers. This border is also a source of geopolitical tension, as China claims a large part of Arunachal Pradesh as part of its territory, referring to it as "South Tibet."
The other northeastern states mentioned in the options—Nagaland, Mizoram, and Manipur—do not share borders with China. Instead, they border Myanmar and, in the case of Mizoram, also Bangladesh. These states are more focused on their relations with Southeast Asian countries rather than China.
Understanding the geographical layout of India's northeastern states and their international borders is crucial for comprehending the geopolitical dynamics of the region. The correct answer, Sikkim and Arunachal Pradesh, highlights the importance of these states in India's relations with China and the strategic significance of their borders.
In summary, the correct answer is (D) Sikkim and Arunachal Pradesh, as these are the only two northeastern states that share international borders with China. This knowledge is essential for students preparing for competitive examinations that test their understanding of Indian geography and international relations.