The correct answer is: b) 15-20% of its geographical area.
Tamil Nadu’s forest cover is approximately 15-20% of its geographical area. This is lower than the national average of 21.7%. The state’s forest cover has been declining in recent years due to deforestation and other factors.
Option a) is incorrect because Tamil Nadu’s forest cover is more than 10% of its geographical area.
Option c) is incorrect because Tamil Nadu’s forest cover is less than 25% of its geographical area.
Option d) is incorrect because Tamil Nadu’s forest cover is less than 35% of its geographical area.