The correct answer is option C, Use shadufs to dig out the reservoir
Shaduf is an ancient method of irrigation still prevalent in some part of India, Egypt, and some other countries. It is a method prevalent in regions where crop production depends on annual rainfall. During rainy season the reservoirs are full but during non-rainy season, the level of water in the reservoir gets low and irrigation becomes difficult. Shaduf is a typically a long tapering pole mounted just like a seesaw. Buckets are hung on this rope at one end and on the other end counterweight are hung. Rope is then pulled down in the reservoir and through the counter weights, buckets along with water are lifted. When the water level is extremely low, a series of shadufs are used.