What was KBC 13's ₹1-cr winning question answered by 19-yr-old Sahil Ahirwar?

Madhya Pradesh's 19-year-old Sahil Ahirwar has become the second contestant to win ₹1 crore on 'Kaun Banega Crorepati' season 13. Sahil was asked, "The Sanskrit phrase 'Atithi Devo Bhava', meaning 'The Guest is God', is taken from which Upanishad?" He won ₹1 crore after giving the correct answer, which is Taittiriya Upanishad.