Explanation
Geologist Robert Bruce Foote discovered a Palaeolithic handaxe at Pallavaram near Madras in 1863, a landmark in Indian prehistoric archaeology. Daya Ram Sahni and John Marshall are associated with Harappan archaeology, while Alexander Cunningham founded the Archaeological Survey’s early work. Robert Bruce Foote fits that evidence because it matches the specific chronology, agency and function contained in the question. A comparison with the alternatives is useful: Daya Ram Sahni, John Marshall and Alexander Cunningham are genuine historical terms or names, but each belongs to a different office, patron, text, region or sequence. The compact memory link is therefore Robert Bruce Foote together with the factual context above, not the isolated option letter.