The correct answer is c) Kosi.
The Kosi is a tributary of the Ganges River in northern India and eastern Nepal. It is known as the “Sorrow of Bihar” due to its history of floods. The Kosi is one of the most destructive rivers in the world, and its floods have displaced millions of people and caused billions of dollars in damage.
The Kosi originates in the Himalayas and flows through Nepal and India before joining the Ganges River near Patna, Bihar. The river is about 700 kilometers long, and its drainage basin covers an area of about 90,000 square kilometers.
The Kosi is a monsoonal river, which means that it experiences most of its flow during the summer monsoon season. The river’s discharge can vary greatly from season to season, and it is prone to flooding during the monsoon season.
The Kosi’s floods are caused by a number of factors, including its steep gradient, its braided channel, and its location in a seismically active region. The river’s steep gradient means that it flows quickly, which makes it more likely to flood. The river’s braided channel means that it has many channels, which makes it difficult to control. The river’s location in a seismically active region means that it is prone to landslides, which can block the river and cause flooding.
The Kosi’s floods have had a devastating impact on the people and environment of Bihar. The floods have displaced millions of people, destroyed homes and crops, and caused billions of dollars in damage. The floods have also made it difficult to develop the region, and they have contributed to the poverty of Bihar.
The Indian government has taken a number of measures to control the Kosi’s floods, including building embankments and dams. However, these measures have not been successful in preventing the floods. The Kosi remains a major threat to the people and environment of Bihar.