The Brahmaputra River and its tributaries are prone to flooding, especially during:

The correct answer is: b) Monsoon season.

The Brahmaputra River is a major river in Asia that flows through China, India, and Bangladesh. It is the ninth longest river in the world and the second longest river in India. The Brahmaputra River is prone to flooding, especially during the monsoon season. The monsoon season is a period of heavy rainfall that occurs in South Asia from June to September. The monsoon rains cause the Brahmaputra River to swell and overflow its banks, which can lead to flooding in the river’s basin.

The other options are incorrect because:

• The summer season is not a time of heavy rainfall in South Asia.
• The winter season is a time of low rainfall in South Asia.
• The post-monsoon season is a time of decreasing rainfall in South Asia.