Which of the following is the most unique feature of the Harappan civilisation?

Town Planning is the right response.

The Ravi River, a stream of the upper Indus area, is close to Harappa.
The drainage system is the most noticeable aspect of the building from the Harappan era. It demonstrates how crucial hygiene was to them.
It was accomplished by connecting a number of drains that ran alongside the streets to bigger sewers in the main thoroughfares.
The planning of the town was fantastic. In certain cities, the center of a residential district is located to the east of citadels situated on a higher platform to the west.
The arrangement of the towns, streets, buildings, brick sizes, drainage, etc., all exhibit homogeneity.
Sites in Harappan cities, such as Mohenjo Daro, Harappa,