The correct option is A D. R. Sahni
The first Harappan sites were discovered in 1920-21 by archaeologists Dr. D. R. Sahni and Dr. R. D. Banerjee (Harappa in Punjab and Mohenjo-Daro in Sind- both in Pakistan now), fresh sites are still being unearthed, adding insights into the rich culture of the Harappan civilization.