The Bardoli Satyagraha was a significant movement led by Sardar Vallabhbhai Patel in 1928 in the Bardoli taluka of Gujarat. The central demand of the movement was the refusal to pay an increased land revenue that was imposed by the British government. The revenue hike was considered exorbitant and unjust by the farmers, who were already struggling with a poor harvest and economic distress.
The movement involved non-violent resistance (Satyagraha), where the farmers refused to pay the increased revenue. The government initially took harsh actions, including confiscating lands and property, but the farmers' resistance gained widespread support, and ultimately, the British government had to relent, reducing the land revenue and returning the confiscated lands.
Thus, the correct answer is (B) Refusal to pay land revenue.