Option 3: Great Britain and the Soviet Union
At the beginning of WW II in 1939, the Allies power consisted of France, Poland, and Britain. Gradually, more nations incorporated on the side of the Allies including Australia, Canada, New Zealand, and South Africa, the Soviet Union, the U.S., and China.
Although the Soviet Union was in a neutral position at the beginning of the war and even helped Germany to invade Poland, the western Soviet Union were later invaded by the Axis power in the operation Barbarossa, in June 1941. And the Soviet Union decided to officially enter the war on the side of the Allies.