Why Was the Winter of 1939-40 Termed a Period of "Phony

Multiple Choice

Why was the winter of 1939-40 termed a period of "phony war?"

A) The revelation of the Soviet-German pact over Poland was revealed.
B) Britain and France declared war on Germany but took no action.
C) The perception was that there was no real war without US involvement.
D) The Soviet Union did not actively fight, but let winter kill off most of their enemies.
E) none of these.