Who among the following advocated the ideology of "oru jati, oru matam, oru daivam manushyanu" (one caste, one religion, one god for humankind)?

Narayana Guru:-  He was a great saint and social reformer of India. He preached for religious unity and social equality in Hinduism.  He is considered to be one of the greatest religious and social leaders of Kerala.  Narayana Guru gave his first sermon in 1884. He preached for religious unity and social equality in Hinduism.  He opposed the caste system, discrimination, and other social evils.  The ideology of "oru jati, oru matam, oru daivam manushyanu" (one caste, one religion, one god for humankind) was advocated by Shri Narayana Guru only.