The leader of the Bar-doli Satyagraha was Sardar Vallabh Bhai Patel. The Bar-doli Satyagraha was a nonviolent protest movement against the British salt tax in the village of Bar-doli in Gujarat, India. Sardar Patel, also known as the Iron Man of India, played a crucial role in organizing and leading this movement.

Option 1, Dr. Rajendra Prasad, and option 2, Pandit Jawaharlal Nehru, were prominent leaders in the Indian independence movement, but they were not directly involved in leading the Bar-doli Satyagraha. Option 4, Acharya J. B. Kripalani, was a leading figure in the Indian National Congress and independence movement, but he was also not the leader of the Bar-doli Satyagraha.

Overall, Sardar Vallabh Bhai Patel, option 3, was the correct leader of the Bar-doli Satyagraha.