The correct answer is: b) Districts in southern Tamil Nadu.
The Mullaperiyar Dam is a masonry dam on the Periyar River in the Indian state of Kerala. It was built in 1895 by the British and is one of the oldest dams in India. The dam is located in the Idukki district of Kerala and is operated by the Tamil Nadu Water and Drainage Board.
The dam is a source of water for irrigation, drinking water, and hydroelectric power generation. It also provides flood control and helps to regulate the flow of the Periyar River. The dam is a major source of water for the districts of Madurai, Theni, Dindigul, and Ramanathapuram in southern Tamil Nadu.
The dam has been the subject of controversy between Kerala and Tamil Nadu for many years. Kerala has been concerned about the safety of the dam and has demanded that it be decommissioned. Tamil Nadu has opposed this demand and has argued that the dam is safe and essential for the water needs of its people.
The Mullaperiyar Dam is a complex issue with a long history. It is a source of water for many people in southern Tamil Nadu, but it has also been the subject of controversy between Kerala and Tamil Nadu.