The correct answer is Nagaland.
Dzukou Valley is a high-altitude valley located on the border between the Indian states of Nagaland and Manipur. It is a unique geological formation, with a landscape of rolling hills, lush forests, and snow-capped peaks. The valley is home to a variety of plant and animal life, including the endangered Dzukou Lily. The Dzukou Valley is also a popular tourist destination, with visitors coming to enjoy the stunning scenery and the opportunity to hike and camp in the wilderness.
The other options are incorrect because they are not located on the border of Manipur. Assam is located to the north of Manipur, Mizoram is located to the south, and Myanmar is located to the east.