Concept:
- A date in a question is often the fastest filter, because it tells you which parts of the world were even in contact at that time.
- Here the date 3000 BCE does almost all the work.
Step 1: Read the date as the main clue.
The blank has to be filled with a region that traders of 3000 BCE could actually reach. That is five thousand years ago, long before ocean-crossing voyages began.
Step 2: Remove every region across an ocean.
Both North America and South America became known to the rest of the world only after the voyages of the late fifteenth century. South Australia lies across the open Indian Ocean. All three are out on the date test alone.
Step 3: Check the one region left on the map.
West Asia sits immediately west of the Indus delta, separated only by the Arabian Sea and the Persian Gulf. Boats could hug the coast the whole way, which is exactly what coastal trade means.
Step 4: Support it with material evidence.
Seals, weights and ornaments of Harappan make have been dug up at West Asian sites, confirming a steady exchange rather than a one-off contact.
Final Answer: (C) West Asia