The correct answer for the Chairman of the Committee on Deepening Digital Payments appointed by the RBI is option-2, Nandan Nilekani.
Option-1, H.R. Khan, is not the correct answer because he is the former Deputy Governor of the Reserve Bank of India (RBI) and there is no information suggesting that he was appointed as the Chairman of the Committee on Deepening Digital Payments.
Option-3, N.R. Narayana Murthy, is also not the correct answer because he is the co-founder of Infosys and there is no information suggesting that he was appointed as the Chairman of the Committee on Deepening Digital Payments.
Option-4, Sanjay Jain, is not the correct answer because there is no information available about his role or appointment as the Chairman of the Committee on Deepening Digital Payments.
Therefore, the correct answer is option-2, Nandan Nilekani, who was appointed as the Chairman of the Committee on Deepening Digital Payments by the RBI.