Final answer:
The Mesopotamian artist likely sourced gold for the fluted bowl from Iran due to the close proximity and trade relations between Mesopotamia and the region that includes modern-day Iran.
Step-by-step explanation:
The Mesopotamian artist likely obtained gold for the fluted bowl from Iran. This deduction is based on the historical context of Mesopotamia, which was situated between the Tigris and Euphrates rivers and included parts of modern-day Iran. During the Bronze Age, Mesopotamia had established trade relations within the region. Moreover, the Persian culture, which had a significant presence in the area of Iran, was known to have been in proximity and interacted with Mesopotamian states. Considering the natural resources available and the interconnectedness of these ancient civilizations, Iran, being rich in natural resources including metals, was a probable source for the gold used by a Mesopotamian artist.