The correct answer is: Drip irrigation.
Drip irrigation is a type of irrigation that delivers water directly to the root zone of plants, either through drippers or micro-sprinklers. This method of irrigation is very efficient, as it minimizes water loss due to evaporation and runoff. It is also very effective in hilly terrain, as it can be used to irrigate crops on slopes without causing erosion.
Flood irrigation is a type of irrigation that involves flooding an entire field with water. This method of irrigation is not very efficient, as much of the water is lost due to evaporation and runoff. It is also not very effective in hilly terrain, as it can cause erosion.
Canal irrigation is a type of irrigation that involves using canals to transport water from a source to a field. This method of irrigation is more efficient than flood irrigation, but it is still not very efficient in hilly terrain.
Groundwater irrigation is a type of irrigation that involves using groundwater to irrigate crops. This method of irrigation is very efficient, as it does not require the use of canals or other infrastructure. However, it is not always possible to access groundwater in hilly terrain.
In conclusion, drip irrigation is the most suitable type of irrigation for Nagaland’s hilly terrain. It is efficient, effective, and can be used on slopes without causing erosion.