Thorn scrub forests are found in:

The correct answer is: a) Hot and dry regions of Tamil Nadu.

Thorn scrub forests are found in hot and dry regions of Tamil Nadu. They are characterized by low rainfall, sparse vegetation, and thorny shrubs. The trees in these forests are usually small and have thick, leathery leaves. The animals that live in thorn scrub forests include antelopes, gazelles, and snakes.

Option b) is incorrect because high-altitude mountainous regions are too cold and dry for thorn scrub forests to grow. Option c) is incorrect because coastal areas are too humid for thorn scrub forests to grow. Option d) is incorrect because the Kaveri Delta is a fertile region with a lot of rainfall.