Correct Answer:
B. Istanbul
Explanation:
The correct answer is Istanbul because it is a globally unique transcontinental metropolis that spans across the continental boundary separating Europe and Asia.
- Step 1 (Geographic Straddling): The city of Istanbul is physically split by the Bosphorus Strait, a vital natural waterway that marks part of the geographic border separating western Asia from eastern Europe.
- Step 2 (Urban Division): The western third of the metropolitan area is located on the European continent, serving as the commercial and historic heart, while the remaining eastern districts extend onto the Asian landmass (Anatolia).
- Incorrect Options:
- Cairo is incorrect because it is a transcontinental city linking Africa (main urban core) and Asia (via the Sinai Peninsula), but holds no territory in Europe.
- Moscow is incorrect because despite being the capital of Russia (which spans both continents), the city of Moscow is located entirely within the European sector of the nation.
- Baku is incorrect because the capital city of Azerbaijan is located geographically on the Absheron Peninsula, placing it entirely on the boundary of Western Asia.