The Harappan site of Ropar (Rupnagar) in Punjab is situated on the banks of the river:

Ropar, now called Rupnagar, is a Harappan site in Punjab, India, situated on the left bank of the Sutlej river, at the foothills of the Shivalik range.

About Ropar:

It was the first Harappan site to be excavated in independent India.

It was excavated by Y. D. Sharma of the Archaeological Survey of India in 1953-1955.

It shows a long sequence of cultures, from the Harappan period through the Painted Grey Ware culture, the Northern Black Polished Ware period, and later historical periods up to the medieval period.

Important finds:

• Harappan pottery, seals, beads, terracotta objects and copper tools.
• A burial in which a dog was buried below a human skeleton, which suggests a close relationship between humans and dogs; this practice is also known from Neolithic sites of Kashmir.
• An oval pit burial.

Harappan sites in Punjab (India):

• Ropar (Rupnagar district).
• Sanghol (Fatehgarh Sahib district), which also has Kushana-period remains.
• Dher Majra and Kotla Nihang Khan.

About the Sutlej river:

• It rises from Rakshastal lake near Mount Kailash in Tibet, where it is called "Langqen Zangbo".
• It enters India through the Shipki La pass in Himachal Pradesh.
• The Bhakra Nangal Dam is built on the Sutlej.
• It joins the Beas at Harike in Punjab, and then flows into Pakistan, where it joins the Chenab to form the Panjnad.
• In the Rigveda, it was called "Shutudri".

Why not the other options?

• ✗The Beas joins the Sutlej at Harike.
• ✗The Ravi is the river of Harappa.
• ✗The Ghaggar has many Harappan sites in Haryana and Rajasthan.