The Shuddhadvaita philosophy is associated with:

Vallabhacharya (1479-1531) was a Vaishnava philosopher and bhakti saint. He was born into a Telugu Brahmin family, at Champaran near Raipur in present-day Chhattisgarh, and spent much of his life in the Braj region (around Mathura and Vrindavan) and at Varanasi.

Vallabha taught Shuddhadvaita, meaning "pure non-dualism". According to him, Brahman is the only reality, and the world and the souls are real expressions of Brahman, not illusions. He identified the supreme Brahman with Lord Krishna. Unlike Shankara's Advaita, Shuddhadvaita does not treat the world as maya; it holds that the whole world is a true and pure form of God.

His path of devotion is called Pushti Marga, the "path of grace". In it, the devotee worships Krishna with loving service (seva) and depends wholly on Krishna's grace (pushti) rather than on rituals or knowledge. The temple of Shrinathji at Nathdwara in Rajasthan is the main centre of the Pushti Marg sect, also called the Vallabha Sampradaya. Vallabha wrote commentaries such as the Anubhashya on the Brahma Sutras and the Subodhini on the Bhagavata Purana.

The blind poet Surdas, author of the Sursagar, was a disciple of Vallabhacharya. Surdas was one of the Ashtachhap, a group of eight poets of the Pushti Marg who composed songs in Braj Bhasha in praise of Krishna. Vallabha's son, Vitthalnath, organised this group.

Why not the other options?

• ✗Ramanujacharya taught Vishishtadvaita (qualified non-dualism).
• ✗Nimbarkacharya taught Dvaitadvaita (dualistic non-dualism) and worship of Radha-Krishna.
• ✗Chaitanya Mahaprabhu of Bengal taught Achintya Bhedabheda and popularised kirtan.