Explanation: Kerala, a state in southern India, is known for its extensive network of rivers that are crucial for its geography, economy, and culture. The rivers in Kerala are categorized based on their length, volume, and the regions they flow through.
1. **Periyar River**: The Periyar is indeed the longest river in Kerala, rising near the Annamalai hills in the Western Ghats. It flows through the districts of Idukki, Ernakulam, and Thrissur before emptying into the Laccadive Sea. However, the statement that it is the longest river in Kerala is correct, but it does not make the entire option correct.
2. **Bharathapuzha River**: The Bharathapuzha, also known as the Nila, is the second longest river in Kerala. It originates in the Anaimalai hills and flows through Palakkad, Thrissur, and Malappuram districts before joining the Arabian Sea. However, it is not the second largest river in terms of volume, which is a common misconception. The Pamba river, while not the longest, is significant for its ecological and cultural importance.
3. **Pamba River**: The Pamba river is one of the most sacred rivers in Kerala, originating from the Peerumedu Pass in the Western Ghats. It flows through the districts of Pathanamthitta and Alappuzha before merging into the Vembanad lake, which is the largest lake in Kerala. This statement is correct, as the Pamba river indeed flows into the Vembanad lake.
In conclusion, the correct answer is that only statement 3 is correct. The Periyar is the longest river in Kerala, but the Bharathapuzha is not the second largest river in terms of volume, and the Pamba river does flow into the Vembanad lake, making it a significant geographical feature of Kerala.