The correct answer is A. Rajkumar Shukla.
Rajkumar Shukla was a peasant leader from Champaran district in Bihar. He was the one who invited Gandhiji to Champaran to help the peasants fight against the oppressive indigo plantation system. Gandhiji’s visit to Champaran in 1917 was a turning point in his life and career. It was during this time that he developed his philosophy of satyagraha, or nonviolent resistance.
Mahadeo Desai was Gandhiji’s personal secretary and close associate. He was a Gujarati lawyer who joined Gandhiji’s non-cooperation movement in 1920. He was one of the most trusted and loyal members of Gandhiji’s inner circle.
Rajendra Prasad was a lawyer and freedom fighter who later became the first President of India. He was one of the founding members of the Indian National Congress and a close associate of Gandhiji.
Narhari Parikh was a Gujarati lawyer and freedom fighter who was also a close associate of Gandhiji. He was one of the founders of the Sabarmati Ashram and a member of the Indian National Congress.
All of the above-mentioned people were close associates of Gandhiji, but it was Rajkumar Shukla who invited him to Champaran.