Which civilization is most closely associated with ancient Harappa?

The Indus Valley civilization is the correct association for ancient Harappa because Harappa is one of the major urban centers that flourished within this civilization, alongside Mohenjo-Daro. The Indus Valley civilization, existing around 2500 BCE to 1900 BCE in what is now Pakistan and northwest India, is known for its advanced urban planning, sophisticated drainage systems, and standardized weights and measures.

Harappa itself showcases several hallmark features of the Indus Valley civilization, such as well-planned cities, large public baths, and a writing system that remains undeciphered. The artifacts and urban structures discovered at Harappa provide vital insights into the social, economic, and cultural practices of the civilization.

Other civilizations listed, such as the Roman, Ancient Greek, and Mesopotamian civilizations, represent different geographical and temporal contexts that do not directly connect with Harappa or the features that define the Indus Valley civilization.