The correct response is: Stalin and Hitler signed the German-Soviet Nonaggression Pact.
Britain's policy of appeasement, particularly towards Hitler's Germany, led to a number of geopolitical consequences, one of which was the signing of the German-Soviet Nonaggression Pact in August 1939. This agreement allowed Hitler to invade Poland without fear of Soviet intervention, leading directly to the outbreak of World War II. The other options provided are incorrect regarding the historical context of appeasement.