The correct answer is option 1, Harappa. Harappa is considered to be one of the earliest cities discovered in India. It was part of the Indus Valley Civilization, which thrived around 2500 BCE. Harappa was located in the Punjab region, which is now in present-day Pakistan. It was an urban settlement with well-planned streets, drainage systems, and multi-story buildings made of bricks. The city had a complex social structure and engaged in various economic activities like trade and agriculture. The discovery of Harappa and its sister city, Mohenjo Daro, played a crucial role in unraveling the existence and importance of the Indus Valley Civilization. They provide valuable insights into the early urbanization and cultural development of ancient India.