The correct option is (c).
Explanation
The vegetation cover of the Ganga-Brahmaputra Basin varies according to the type of landform and the amount of rainfall received. The region supports a diverse range of flora, transitioning from the plains to the deltaic regions.
- Statement 1 is Correct: The Ganga and Brahmaputra plains are dominated by tropical deciduous forests. These forests shed their leaves during the dry season to conserve water. Common tree species found in these plains include teak, sal, and peepal.
- Statement 2 is Incorrect: Bamboo groves are a distinct and prominent feature of the Brahmaputra plain. Contrary to the statement, thick bamboo groves are common in this region, not absent.
- Statement 3 is Correct: The delta area, specifically the Sundarbans formed by the Ganga and Brahmaputra rivers, is covered with mangrove forests. These forests are adapted to saline water and tidal influences. The Sundari tree is a characteristic species of this region, after which the Sundarbans are named.
Key Takeaway: The Ganga-Brahmaputra Basin is characterized by tropical deciduous forests (Teak, Sal) in the plains, extensive bamboo groves in the Brahmaputra region, and mangrove forests in the deltaic areas.