The correct answer is: D. Ranchi district.
The Ajay River is a river in the Indian state of Jharkhand. It originates in the Ranchi district and flows through the districts of Gumla, Lohardaga, and Palamu before joining the Son River in the Garhwa district. The Ajay is a tributary of the Son River, which is a tributary of the Ganges River.
The Ajay River is a major source of irrigation for the districts through which it flows. It is also a popular destination for fishing and boating.
The Ajay River is a beautiful river with a rich history and culture. It is a vital part of the ecosystem of Jharkhand and is an important source of water for the people of the state.
The other options are incorrect because:
- Munger district is located in the state of Bihar.
- Palamu district is located in the state of Jharkhand.
- Dumka district is located in the state of Jharkhand.