In India, which of the following geographical regions has the lowest elevation?

Kundanad (part of Kerala's coastal lowlands) lies in the lowland coastal plains of India and therefore has the lowest elevation among the listed regions. Some nearby coastal areas, for example Kuttanad in Kerala, are known for being at or below sea level, which illustrates how low these coastal plains are compared with inland uplands and hilly regions. Kongu Nadu: consists of undulating plains and some hills in western Tamil Nadu; generally higher than coastal lowlands.

Palnadu: an inland upland region in Andhra Pradesh with higher, undulating terrain.

Malenad (Malenadu): the hilly Western Ghats region, with much higher elevation than coastal plains.