Answer:
D.favorable balance of trade
Explanation:
The revolution in Russia is the one among the following choices that was one cause of the outbreak of Red scare.
"The reason why Britain didn’t declare war on the Soviet Union is an
intriguing one. Unknown to the general public there was a ‘secret
protocol’ to the 1939 Anglo-Polish treaty that specifically limited the
British obligation to protect Poland to ‘aggression’ from Germany" http://www.historyextra.com/qa/why-did-britain-and-france-not-declare-war-soviet-union-when-red-army...
This was a quote after WWI, the "war to end all wars". At the end of the war, Germany was basically blamed for the war in the Treaty of Versailles. They had to pay an immense amount of money to the other countries. In WWII, Germany got its "revenge".
