I would say B because none of the others are even close.
After WW2 Germany was devided into 2 countries
The open door policy was designed to open Japan to American trade and influence (The US was hungry for an imperial puppet).
In 1945, after the defeat of Nazi Germany, Poland's borders were redrawn in accordance with the decisions made first by the Allies at the Tehran Conference of 1943 where the Soviet Union demanded the recognition of the military outcome of the top secret Nazi–Soviet Pact of 1939 of which the West was unaware. Hope this helps :)
Answer:
<em>A. 2</em><em> </em><em>years</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em>