original_query: What was the reason given by Dr. Köster for the French to evacuate Frankfurt, Darmstadt, and Homburg?
query: What was the reason given by Dr. Köster for the French to evacuate Frankfurt, Darmstadt, and Homburg?
answer: Dr. Köster stated that the German troops had been reduced to 17,500, which was permitted by the agreement of August 1919, and therefore the French should evacuate the occupied towns.