Explanation: The Western Ghats, also known as Sahyadri, is a mountain range that runs along the western edge of the Indian peninsula, extending from the Tapti River in the north to the Kanyakumari in the south. This mountain range is a significant geographical feature that influences the climate, biodiversity, and overall landscape of the states it borders, including Kerala.
The Western Ghats are a UNESCO World Heritage Site and are known for their rich biodiversity, with a high level of endemism. They are home to a variety of flora and fauna, including several endangered species. The mountain range plays a crucial role in the water cycle of the region, acting as a barrier to the monsoon winds and causing heavy rainfall on the windward side, which is the western part of Kerala.
In the context of Kerala, the Western Ghats form the eastern boundary of the state, running along its length. They are a natural barrier that separates Kerala from the Deccan Plateau. The mountain range influences the climate of Kerala, contributing to the state's high rainfall and lush greenery. The Western Ghats are also a source of several rivers that flow through Kerala, including the Periyar, Bharathappuzha, and Pamba.
The Eastern Ghats, on the other hand, are located on the eastern side of India and do not border Kerala. They are situated in the eastern coastal plains and are not a significant geographical feature for Kerala. The Himalayas, the world's highest mountain range, are located in the northern part of India and do not border Kerala either.
Therefore, the correct answer is the Western Ghats, as they are the mountain range that borders Kerala and significantly influences its geographical and ecological characteristics.