The correct option is D Arya Samaj started a movement to reconvert people who had converted to Islam and Christianity from Hinduism.
The Arya Samaj was formed in 1875 by Swami Dayanand Saraswati. It promoted the values and practices based on the belief in the infallible authority of the Vedas. The members of the Arya Samaj rejected idolatry, caste system, empty ritualism, and the man-made dictates on women. In this organisation, cow protection associations were formed to prevent them from slaughter. It also launched the Shuddhi Movement to reconvert the people who converted to Islam and Christianity from Hinduism.