Who was known as ‘Frontier Gandhi’?

The correct option is Khan Abdul Ghaffar Khan.

Khan Abdul Ghaffar Khan (1890–1988) was a prominent Pashtun independence activist who campaigned against British colonial rule in India. He was a close friend and follower of Mahatma Gandhi, advocating for non-violent resistance. Due to his similar adherence to Gandhian principles, philosophy, and methods of non-violence in the North-West Frontier Province (NWFP) of British India, he earned the nickname "Frontier Gandhi" (or Sarhadi Gandhi).

He also founded the Khudai Khidmatgar (Servants of God) movement, commonly known as the "Red Shirts," which actively participated in the Indian nationalist struggle using non-violent means.