The correct answer is b) Palakkad.
Palakkad district has the largest area under irrigation in Kerala. It is followed by Thrissur, Malappuram, and Kannur districts.
Palakkad district is located in the central part of Kerala. It is the largest district in Kerala in terms of area. The district is known for its fertile land and its rich agricultural produce. The main crops grown in Palakkad district are paddy, sugarcane, and coconut.
The district has a well-developed irrigation system. The main sources of irrigation in Palakkad district are canals, tanks, and wells. The canals are the main source of irrigation in the district. The canals are fed by the rivers Bharathapuzha, Achankovil River, and Malampuzha River. The tanks are also an important source of irrigation in the district. The tanks are mainly used for irrigation of paddy fields. The wells are also used for irrigation of paddy fields and other crops.
The irrigation system in Palakkad district has helped to increase the agricultural production in the district. The district is now one of the major producers of paddy, sugarcane, and coconut in Kerala.