Which region supplied copper to the inhabitants of the Harappa?

Khetri

The correct answer is Option (4) → Khetri

"The Harappans procured materials for craft production in various ways. For instance, they established settlements such as Nageshwar and Balakot in areas where shell was available. Other such sites were Shortughai, in far-off Afghanistan, near the best source of lapis lazuli, a blue stone that was apparently very highly valued, and Lothal which was near sources of carnelian (from Bharuch in Gujarat), steatite (from south Rajasthan and north Gujarat) and metal (from Rajasthan). Another strategy for procuring raw materials may have been to send expeditions to areas such as the Khetri region of Rajasthan (for copper) and south India (for gold). These expeditions established communication with local communities. Occasional finds of Harappan artefacts such as steatite micro beads in these areas are indications of such contact. There is evidence in the Khetri area for what archaeologists call the Ganeshwar-Jodhpura culture, with its distinctive non-Harappan pottery and an unusual wealth of copper objects. It is possible that the inhabitants of this region supplied copper to the Harappans.".