The correct answer is D. Champaran.
Gandhiji started the first Satyagraha Movement from Champaran, Bihar in 1917. The movement was against the British indigo planters who were forcing the peasants to grow indigo on their lands. The peasants were not paid fairly for their work and were often subjected to violence and intimidation. Gandhiji’s movement was successful in getting the British government to abolish the indigo contract system.
The other options are incorrect. Patna is the capital of Bihar. Gaya is a city in Bihar. Madhubani is a district in Bihar.