The correct answer is option 'A' - Son river.

Son River:
The Son river is a major river in central India, flowing from south to north. It is one of the longest rivers in India and the largest tributary of the Ganges. Here are some key points about the Son river:

- Origin: The Son river originates from the Amarkantak plateau in Madhya Pradesh. It is formed by the confluence of two rivers - the Mahanadi and the Koel.

- Flow: The Son river flows in a northerly direction through the states of Madhya Pradesh, Chhattisgarh, Jharkhand, and Bihar. It eventually joins the Ganges near Patna, the capital city of Bihar.

- Length: The Son river has a total length of about 784 kilometers. It passes through various cities and towns, including Jabalpur, Bilaspur, Ranchi, and Dehri-on-Son.

- Tributaries: The Son river has several tributaries, including the North Koel, the South Koel, the Rihand, and the Sonebari. These tributaries contribute to the overall flow of the river and its drainage basin.

- Significance: The Son river plays a vital role in the agricultural and economic activities of the regions it passes through. It provides irrigation water for farming and is also used for fishing and transportation. The river has significant hydropower potential, and several dams have been constructed along its course for generating electricity.

- Environmental concerns: Like many rivers in India, the Son river faces environmental challenges such as pollution from industrial and domestic waste. Efforts are being made to address these issues and restore the ecological health of the river.

In conclusion, the Son river is the correct answer as it flows from south to north. It is a major river in central India, originating from the Amarkantak plateau and joining the Ganges near Patna.