The correct answer is: c) Dimapur Valley.
The Dimapur Valley is a significant valley region in Nagaland known for its fertile plains. It is located in the central part of the state, and is home to the capital city of Dimapur. The valley is drained by the Dhansiri River, and is a major agricultural region. The Dimapur Valley is also home to a number of important cultural and historical sites, including the Kachari Fort and the Dimapur Cathedral.
The Dzukou Valley is a high-altitude valley located in the Naga Hills. It is known for its beautiful scenery and its role in the Naga independence movement. The Tizu Valley is a valley located in the Tuensang district of Nagaland. It is known for its scenic beauty and its traditional Naga villages. The Barak Valley is a valley located in the state of Assam. It is known for its fertile plains and its tea plantations.
The Dimapur Valley is the largest and most important valley in Nagaland. It is a major agricultural region, and is home to a number of important cultural and historical sites. The valley is also a significant transportation hub, and is connected to the rest of India by road and rail.