The correct option is (c).
Explanation
The vegetation cover of the Ganga-Brahmaputra basin varies significantly according to the type of landforms and climatic conditions, ranging from tropical deciduous forests in the plains to coniferous forests in the higher altitudes.
- Statement 1 is Incorrect: Sal and Teak are tropical deciduous trees, not coniferous trees. While tropical deciduous forests are indeed found in the Ganga-Brahmaputra plains, coniferous trees are distinct gymnosperms with needle-like leaves, typically found in colder climates.
- Statement 2 is Correct: The Brahmaputra plain is characterized by high rainfall and humidity. Consequently, thick bamboo groves are a common and dominant feature of the vegetation in this region.
- Statement 3 is Correct: In the mountainous regions of the basin (such as the Himalayas), where the temperature is low and slopes are steep, coniferous trees like Pine, Deodar, and Fir are found. These trees are adapted to cool climates and high altitudes.
Key Takeaway: The Ganga-Brahmaputra basin supports Tropical Deciduous forests (Sal, Teak, Peepal) in the plains, while Coniferous forests (Pine, Deodar, Fir) are restricted to the cooler, mountainous Himalayan regions.