The correct answer is B. Bhopal.
Bhopal was a princely state in India, with its capital at Bhopal. It was founded in 1707 by Dost Mohammad Khan, a Pashtun soldier who served under the Mughal Empire. The state was ruled by the Bhopal dynasty until 1949, when it acceded to the Indian Union.
Gwalior was a princely state in India, with its capital at Gwalior. It was founded in the 7th century by the Tomar Rajputs. The state was ruled by the Tomars, the Kachhwahas, and the Scindias until 1949, when it acceded to the Indian Union.
Holkar was a Maratha clan that ruled over the princely state of Indore in India. The Holkars were founded by Malhar Rao Holkar, who served under the Maratha leader Shivaji Maharaj. The Holkars ruled over Indore from 1721 to 1948, when it acceded to the Indian Union.
Rewa was a princely state in India, with its capital at Rewa. It was founded in the 16th century by the Bundela Rajputs. The state was ruled by the Bundelas until 1949, when it acceded to the Indian Union.