The correct answer is c) Periyar River.
The Thattekad Bird Sanctuary is a bird sanctuary located in the Idukki district of Kerala, India. It is one of the most important bird sanctuaries in India, and is home to over 200 species of birds. The sanctuary is located on the banks of the Periyar River, and is a popular tourist destination.
The Manimala River is a river in Kerala, India. It is a tributary of the Periyar River. The river is about 100 kilometers long, and flows through the districts of Idukki, Kottayam, and Ernakulam.
The Pamba River is a river in Kerala, India. It is a tributary of the Achencoil River. The river is about 150 kilometers long, and flows through the districts of Pathanamthitta, Alappuzha, and Kottayam.
The Bharathappuzha River is the longest river in Kerala, India. It is about 200 kilometers long, and flows through the districts of Palakkad, Thrissur, Malappuram, and Kozhikode.