The largest hydropower project in Nagaland is located on the:

Doyang River
Dhansiri River
Dikhu River
Tizu River

The correct answer is: a) Doyang River.

The Doyang Hydroelectric Project is a 120 MW hydroelectric power plant located on the Doyang River in Wokha district, Nagaland, India. The project was commissioned in 2001 and is owned and operated by the North Eastern Electric Power Corporation Limited (NEEPCO).

The Doyang River is a tributary of the Brahmaputra River. It originates in the Patkai Hills and flows through the states of Nagaland and Assam. The river is about 200 kilometers long and has a drainage basin of about 4,000 square kilometers.

The Doyang Hydroelectric Project is a run-of-the-river project. This means that the project does not store any water. The water from the river is diverted through a canal to a powerhouse, where it is used to turn a turbine. The turbine generates electricity, which is then transmitted to the grid.

The Doyang Hydroelectric Project has a number of benefits. It provides clean and renewable energy, and it helps to reduce the demand for electricity from fossil fuels. The project also provides employment for local people and helps to boost the local economy.

However, the project also has a number of environmental impacts. The construction of the dam has led to the displacement of people and wildlife. The dam also blocks the migration of fish, and it has caused changes in the water quality of the river.

Overall, the Doyang Hydroelectric Project is a controversial project. It has both positive and negative impacts. It is important to weigh the benefits and costs of the project before making a decision about whether or not to support it.

The other options are incorrect because they are not the location of the largest hydropower project in Nagaland. The Dhansiri River is located in Assam, the Dikhu River is located in Nagaland, and the Tizu River is located in Arunachal Pradesh.