Correct Answer: Klemens von Metternich
Subject: 2025
Explanation: <b>Key Fact</b><br>The Congress of Vienna (1814–1815) was chaired by Austrian Chancellor Klemens von Metternich to restore European balance of power after the Napoleonic Wars.<br><br><b>Additional Info</b><br>Topic: European & World History.<br><br><b>Why the other options are wrong</b><br>Option A: Napoleon III ruled France much later (1852–1870).<br>Option B: Sun Yat-sen was the father of the Republic of China (20th century).<br>Option C: Talleyrand represented France as a diplomat, but did not preside.<br>Option D: Correct.<br><br><b>Exam Trick</b><br>Congress of Vienna = Austrian Chancellor Metternich.<br><br><b>Final Answer</b><br>Option D — Klemens von Metternich.