The correct answer is: A. Damodar and Son rivers.
The Damodar and Son rivers are two of the major rivers in Jharkhand, India. They are both formed after the melting of glaciers in the Carboniferous period. The Damodar River is a major tributary of the Ganges River, while the Son River is a major tributary of the Chambal River. Both rivers are important sources of water for irrigation and drinking water in Jharkhand.
The Ajay and Sankh rivers are also two of the major rivers in Jharkhand, but they were not formed after the melting of glaciers in the Carboniferous period. They were formed after the collision of the Indian and Eurasian plates in the Tertiary period. The Ajay River is a tributary of the Damodar River, while the Sankh River is a tributary of the Son River. Both rivers are important sources of water for irrigation and drinking water in Jharkhand.
The Mayurakshi River is a major river in West Bengal, India. It is not a major river in Jharkhand. It was formed after the collision of the Indian and Eurasian plates in the Tertiary period. The Mayurakshi River is a tributary of the Bhagirathi River, which is a tributary of the Ganges River. The Mayurakshi River is an important source of water for irrigation and drinking water in West Bengal.