The Azadi Tower in Tehran, completed in 1971, was built to commemorate what?
AThe Constitutional Revolution
BThe nationalization of oil
CThe founding of Tehran
D2,500 years of the Persian Empire✓
Originally named the Shahyad Tower, it anchored the 1971 celebrations of 2,500 years of monarchy since Cyrus the Great; it was renamed Azadi ('Freedom') after 1979.