The correct answer is option 2: Indigo. The first Satyagraha movement in India began in Champaran, Bihar, to oppose the British Raj`s indigo plantations. Indigo was an important cash crop at that time, and the British imposed unfair and exploitative conditions on the local farmers who were forced to cultivate indigo on their land.

The indigo plantations involved a system called the "tinkathia" system, where a portion of the cultivable land was forcefully used for indigo cultivation. The farmers were forced to grow indigo instead of food crops, leading to a scarcity of food and economic hardship. This oppressive system prompted Mahatma Gandhi to launch the Satyagraha movement, advocating for the rights of the peasants and demanding fair treatment and improved conditions for the farmers.

The movement in Champaran was a significant milestone in India`s freedom struggle and marked the beginning of Gandhian nonviolent resistance against colonial rule.