Which feature was widespread—but not identical—across major Harappan urban settlements?

Major Harappan settlements display planned streets, drains, standardised bricks and organised neighbourhoods. Their plans nevertheless varied with local topography and function. Calling the civilisation urban and planned is sound; claiming one perfectly uniform grid for every settlement is not. Planned streets, drainage and standardised construction practices fits that evidence because it matches the specific chronology, agency and function contained in the question. A comparison with the alternatives is useful: One identical grid imposed on every settlement, Monumental royal palaces in each city and Iron fortifications around all villages 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 Planned streets, drainage and standardised construction practices together with the factual context above, not the isolated option letter.