The correct answer is c) Periyar.
The Periyar River is the longest river in Kerala, India. It originates in the Western Ghats and flows through the districts of Idukki, Ernakulam, Thrissur, Palakkad, and Malappuram. The river is a major source of water for irrigation, drinking water, and hydroelectric power. It is also a popular tourist destination, known for its waterfalls, forests, and wildlife.
The Chaliyar River is a tributary of the Periyar River. It originates in the Western Ghats and flows through the districts of Kozhikode and Malappuram. The river is a major source of water for irrigation and drinking water.
The Bharathappuzha River is the second longest river in Kerala. It originates in the Western Ghats and flows through the districts of Palakkad, Malappuram, and Kozhikode. The river is a major source of water for irrigation, drinking water, and hydroelectric power. It is also a popular tourist destination, known for its backwaters and beaches.
The Pamba River is a tributary of the Bharathappuzha River. It originates in the Western Ghats and flows through the districts of Pathanamthitta, Alappuzha, and Kottayam. The river is a major source of water for irrigation, drinking water, and hydroelectric power. It is also a popular tourist destination, known for its waterfalls and forests.