The correct answer is A. Rajmahal.
Rajmahal was the capital of the Bengal Sultanate from 1324 to 1576. It was also the capital of the Mughal province of Bengal from 1576 to 1608. The city was founded by Sultan Shamsuddin Ilyas Shah in 1324. It was located on the banks of the Ganges River, about 200 kilometers north of Kolkata.
Rajmahal was a major center of trade and commerce. It was also a center of Islamic learning. The city was surrounded by a strong wall and had several palaces, mosques, and other buildings.
In 1608, the Mughal emperor Jahangir moved the capital of Bengal to Agra. Rajmahal declined in importance after that. However, it remained a significant city until the 18th century.
The other options are incorrect.
B. Ranchi is the capital of the Indian state of Jharkhand.
C. Palamu is a district in the Indian state of Jharkhand.
D. Daltonganj is a town in the Indian state of Jharkhand.