Step 1: Identifying the correct option:
Champaran is a district in Bihar. In 1917, Mahatma Gandhi led the Champaran Satyagraha there in support of indigo farmers being forced to grow indigo under exploitative conditions by British planters - his first Satyagraha movement on Indian soil.
Step 2: Why the other options are wrong:
Gujarat is linked to Gandhi's later Kheda and Bardoli Satyagrahas; West Bengal and Uttar Pradesh are not the location of the Champaran movement.
Final Answer:
Bihar (Option C)