Correct Option: A

The Son originates near Amarkantak in Madhya Pradesh, just east of the headwater of the Narmada River, and flows north-northwest through Madhya Pradesh state before turning sharply eastward where it encounters the southwest-northeast-running Kaimur Range. The Son river at 784 kilometres (487 mi) long, is one of the largest rivers of India. Its chief tributaries are the Rihand and the North Koel.