Drona was a measure of capacity used especially for grain. It should not be confused with nishka, which was an ornament or unit of value, or with measures associated with land, cloth or time. Grain fits that evidence because it matches the specific chronology, agency and function contained in the question. A comparison with the alternatives is useful: Cloth, Time and Land are genuine historical terms or names, but each belongs to a different office, patron, text, region or sequence. Reading the question as a relationship among person, period, place and institutional purpose prevents that mistake. The compact memory link is therefore Grain together with the factual context above, not the isolated option letter.