The correct answer is Canals. Tubewells irrigation makes it possible to irrigate a much larger area. Groundwater is easily available under tubewell irrigation. The water table is fairly close to the surface. During periods of drought, as the surface water dries up due to no rainfall the tubewell irrigation is more reliable than other types of irrigation. This method of irrigation is suitable for smallholdings. The district of Ambala is dependent on irrigation on Canals. Canals building leads to the development of the un-irrigated wasteland. During the fluctuations in rainfall intensity, the water requirement of crops can be met by having a proper system of irrigation. It also serves other purposes such as hydroelectricity, drinking water supply, fishery development, and navigation. The construction of canals required economic investment and time.