Most rivers in Tamil Nadu are dependent on rainfall, making them:

Perennial
Seasonal
Glacier-fed
Tidal

The correct answer is: b) Seasonal.

Most rivers in Tamil Nadu are seasonal because they are dependent on rainfall. The monsoon rains that occur in the region from June to September are the main source of water for these rivers. During the monsoon season, the rivers are full and flowing, but they dry up during the rest of the year.

A perennial river is a river that flows all year round. These rivers are typically fed by glaciers or snowmelt. Glacier-fed rivers are found in mountainous regions, while snowmelt-fed rivers are found in high-latitude regions.

A tidal river is a river that is affected by the tides. The tides cause the water level in the river to rise and fall. Tidal rivers are found in coastal areas.

A seasonal river is a river that flows only during certain times of the year. These rivers are typically fed by rainfall. Seasonal rivers are found in many parts of the world, including Tamil Nadu.