Concept:
This question requires matching significant 20th-century historical and political events with their correct dates.
Step 1: Evaluating the Correct Pairs.
• B. Treaty of Versailles (1919): Correct. This peace treaty ended World War I between Germany and the Allied Powers, famously redrawing the map of Europe.
• D. Berlin Wall erected (1961): Correct. The German Democratic Republic (East Germany) began building the wall in August 1961 to prevent citizens from fleeing to West Berlin.
Step 2: Evaluating the Incorrect Pairs.
• A. Nuremberg Trials began (1956): Incorrect. The Nuremberg Trials, where prominent members of the Nazi leadership were prosecuted, took place between 1945 and 1946, immediately following World War II.
• C. Chinese Revolution (1917): Incorrect. 1917 was the year of the Russian Revolution. The Chinese Communist Revolution culminated in the establishment of the People's Republic of China in 1949 (though the earlier Xinhai Revolution occurred in 1911).
Step 3: Conclusion.
Only pairs B and D are factually accurate. Therefore, Option (1) is the correct answer.