The answer to this question is "Britain blockaded Germany."
The explanation to this answer is that from 1914 up to 1919 the Allies restricted the supply of goods to Germany, causing disease and starvation in Germany. The British Royal Navy was bigger, stronger and more powerful than the German Kaiserliche Marine.
So the correct order of all the events from the question is:
-Britain blockaded Germany.
-The stalemate broke.
-Germany was forced to retreat.
-The armistice was signed.
Real gross domestic product (GDP) is an inflation-adjusted measure that reflects the value of all goods and services produced by an economy in a given year, expressed in base-year prices, and is often referred to as "constant-price," "inflation-corrected" GDP or "constant dollar GDP."
https://www.investopedia.com/terms/r/realgdp.asp
1. Indonesia - Krakatau
2. Nepal - Mount Everest
3. China - Yangtze River
4. Pakistan - Khyber Pass
5. Japan - Mount Fuji
6. India - Ganges River
