“Our national policy is this: First, by an impressive expression of the public will and without regard to partisanship, we are committed to all-inclusive national defense.
Second, by an impressive expression of the public will and without regard to partisanship, we are committed to full support of all those resolute peoples, everywhere, who are resisting aggression and are thereby keeping war away from our Hemisphere. By this support, we express our determination that the democratic cause shall prevail; and we strengthen the defense and the security of our own nation.
Third, by an impressive expression of the public will and without regard to partisanship, we are committed to the proposition that principles of morality and considerations for our own security will never permit us to acquiesce in a peace dictated by aggressors and sponsored by appeasers. We know that enduring peace cannot be bought at the cost of other people's freedom.”

— Franklin Delano Roosevelt, State of the Union Address, January 1941
Which of these events most directly contributed to the national policy as proposed by Roosevelt in this address?

A) the signing of the Nazi-Soviet Non-Aggression Pact
B) the Japanese invasion of Manchuria and the Nanking Massacre
C) the German defeat at the Battles of Stalingrad and Leningrad
D) the fall of France, Belgium, and the Netherlands and the Battle of Britain