The correct answer is: b) Periyar River.
The Idukki Dam is a gravity dam on the Periyar River in the Indian state of Kerala. The dam is 136 meters (446 ft) high and 360 meters (1,181 ft) long, and it is the highest arch dam in Asia. The dam was built between 1961 and 1974, and it is used for hydroelectric power generation, irrigation, and flood control.
The Periyar River is a major river in Kerala. It originates in the Western Ghats and flows through the state before joining the Arabian Sea. The river is a major source of water for irrigation and drinking water in Kerala. It is also a popular tourist destination, and there are many waterfalls and dams on the river.
The other options are incorrect because they are not rivers in Kerala. The Kabini River is a river in Karnataka, the Pamba River is a river in Kerala, and the Chaliyar River is a river in Kerala.