Mahatma Gandhi gave up the title of Kaiser-i-Hind and returned all the war medals which were awarded to him by the British for his war services (during the First World War)?

A) in protest against the Jallianwala Bagh tragedy B) during the Non-Cooperation Movement C) in support of the Khilafat demand when the Central Khilafat Committee organised a general all-India hartal on August 1, 1920 D) during the Champaran Satyagraha