Daya Ram Sahni began the major excavation of Harappa in 1921. Banerji is associated with Mohenjodaro, John Marshall announced the civilisation’s discovery to the wider world and R. Daya Ram Sahni fits that evidence because it matches the specific chronology, agency and function contained in the question. A comparison with the alternatives is useful: Rakhaldas Banerji, John Marshall and R. Bisht are genuine historical terms or names, but each belongs to a different office, patron, text, region or sequence. The compact memory link is therefore Daya Ram Sahni together with the factual context above, not the isolated option letter.