Step 1: Understanding the Question:
This is a cultural geography question about the traditional water festivals (Vallam Kali) of Kerala and the specific rivers on which they are held.
Step 2: Key Formulas and approach:
Locate the geographic region of Aranmula, Pathanamthitta district, and identify the main river flowing through this heritage village.
Step 3: Detailed Explanation:
• The Aranmula Boat Race (Aranmula Vallam Kali) is the oldest and most traditional river boat festival in Kerala.
• It is held annually during the Onam festival season near the Aranmula Parthasarathy Temple.
• The event takes place on the Pamba River, which flows through Pathanamthitta.
• Unlike competitive boat races like the Nehru Trophy (held on Punnamada Lake), the Aranmula Boat Race is highly ritualistic and focused on temple traditions.
• The other options, Periyar (flowing through Ernakulam/Idukki), Chaliyar (Malappuram/Kozhikode), and Bharathapuzha (Nila, flowing through Palakkad/Malappuram), do not host the Aranmula Boat Race.
Step 4: Final Answer:
The Aranmula Boat Race is conducted on the river Pamba, making Option (B) the correct choice.