The correct answer is Ramgarh.
Ramgarh was a princely state in India that merged with the Indian Union after a peasant revolt in 1949. The revolt was led by the Kisan Sabha, a peasant organization that was fighting for land reform and better working conditions for peasants. The revolt was successful in forcing the Maharaja of Ramgarh to agree to a number of reforms, including the redistribution of land and the establishment of a minimum wage for peasants. The revolt also led to the merger of Ramgarh with the Indian Union.
Dumraon was a princely state in India that merged with the Indian Union in 1947. Sonbarsa was a princely state in India that merged with the Indian Union in 1948. Tekari was a princely state in India that merged with the Indian Union in 1949.
The peasant revolt in Ramgarh was one of a number of peasant revolts that took place in India in the late 1940s and early 1950s. These revolts were part of a larger movement for land reform and social justice that was taking place in India at the time. The revolts were successful in forcing the Indian government to enact a number of reforms, including the Land Reform Act of 1950, which redistributed land to millions of peasants.