What evidence suggests a connection between Oman and the Harappan civilization?

Chemical analysis showing traces of nickel in Omani copper and Harappan artefacts

The correct answer is Option 2 - Chemical analysis showing traces of nickel in Omani copper and Harappan artefacts

Recent archaeological finds suggest that copper was also probably brought from Oman, on the southeastern tip of the Arabian peninsula. Chemical analyses have shown that both the Omani copper and Harappan artefacts have traces of nickel, suggesting a common origin. There are other traces of contact as well. A distinctive type of vessel, a large Harappan jar coated with a thick layer of black clay has been found at Omani sites. Such thick coatings prevent the percolation of liquids. We do not know what was carried in these vessels, but it is possible that the Harappans exchanged the contents of these vessels for Omani copper. Mesopotamian texts datable to the third millennium BCE refer to copper coming from a region called Magan, perhaps a name for Oman, and interestingly enough copper found at Mesopotamian sites also contains traces of nickel.