The correct answer is: A. Rohtak.
On 6th April, 1919, a big conference was held against the Rowlatt Act in Rohtak. The conference was organized by the Indian National Congress and was attended by a large number of people. The main purpose of the conference was to protest against the Rowlatt Act, which was seen as a draconian law that gave the British government excessive powers. The conference was also a call for unity among Indians and for them to stand up against British rule.
The Rowlatt Act was passed by the British government in 1919. The act gave the government the power to detain people without trial and to suppress any form of dissent. The act was widely seen as a violation of civil liberties and was met with widespread protests in India.
The Rohtak conference was one of the many protests that were held against the Rowlatt Act. The conference was a success in that it helped to raise awareness of the act and to mobilize people against it. The act was eventually repealed in 1922, but the Rohtak conference remains an important event in the history of Indian independence.
The other options are incorrect because they are not the places where the conference was held.