Final answer:
The Soviet Union signed a nonaggression pact with Germany, known as the Molotov-Ribbentrop Pact, that led to the invasion and division of Poland between Germany and the Soviet Union in 1939.
Step-by-step explanation:
Regarding the question Which nation(s) signed a nonaggression pact with Germany that led to the invasion and division of Poland?, the correct answer is d) the Soviet Union. In August of 1939, a crucial diplomatic agreement known as the Molotov-Ribbentrop Pact, or the Nazi-Soviet Pact, was signed between Nazi Germany and the Soviet Union. This pact included a secret protocol for the division of territories in Eastern Europe, including Poland. Adolf Hitler and the Soviet Premier Joseph Stalin agreed to not attack each other and to remain neutral should either party get involved in a war. This nonaggression pact effectively paved the way for Germany to initiate its invasion of Poland from the west without fear of Soviet intervention. It wasn't long after the German assault began in September that the USSR invaded Poland from the east according to their agreement, leading to the subjugation and division of Poland between the two powers.