A social reformer and founder of the Arya Samaj in Karnataka:

Swami Vivekananda
Dayananda Saraswati
Raja Ram Mohan Roy
Ishwar Chandra Vidyasagar

The correct answer is B. Dayananda Saraswati.

Dayananda Saraswati was a Hindu reformer and the founder of the Arya Samaj. He was born in Gujarat, India in 1824. He was a child prodigy and learned Sanskrit, the Vedas, and other Hindu scriptures at a young age. He was also a critic of Hinduism and believed that it had become corrupt. He founded the Arya Samaj in 1875 to reform Hinduism and return it to its original Vedic roots. The Arya Samaj promoted education, widow remarriage, and women’s rights. It also opposed caste discrimination. Dayananda Saraswati died in 1883.

A is incorrect. Swami Vivekananda was a Hindu monk and the chief disciple of Ramakrishna. He was born in Kolkata, India in 1863. He was a charismatic preacher and traveled to the United States and Europe to spread Hinduism. He founded the Ramakrishna Mission in 1897. Swami Vivekananda died in 1902.

C is incorrect. Raja Ram Mohan Roy was a Bengali polymath who is considered the father of modern India. He was born in 1772 in Calcutta, India. He was a social reformer, religious reformer, and a pioneer of Indian nationalism. He founded the Brahmo Samaj in 1828 to reform Hinduism. Raja Ram Mohan Roy died in 1833.

D is incorrect. Ishwar Chandra Vidyasagar was a Bengali polymath who is considered one of the greatest educators and reformers in Indian history. He was born in 1820 in Birbhum district, Bengal Presidency, British India. He was a scholar, writer, and social reformer. He worked for the upliftment of women and widows. He also promoted education and widow remarriage. Ishwar Chandra Vidyasagar died in 1891.