The correct answer is: d) Traditional rainwater harvesting.
Traditional rainwater harvesting is the primary method of irrigation used in Mizoram. It is a method of collecting and storing rainwater for later use. This is done by building small dams or reservoirs on hills or mountains. The water is then collected in tanks or ponds and used to irrigate crops.
Canal irrigation is a method of irrigation in which water is transported from a source, such as a river or lake, to fields through a network of canals. This method is often used in large-scale agriculture.
Drip irrigation is a method of irrigation in which water is delivered directly to the roots of plants through a network of small pipes. This method is more efficient than canal irrigation because it uses less water.
Sprinkler irrigation is a method of irrigation in which water is sprayed onto crops from above. This method is often used in large-scale agriculture.
Traditional rainwater harvesting is the most sustainable method of irrigation because it does not require the use of any external resources. It is also the most efficient method of irrigation because it uses the water that is naturally available.