(A) 1914
(B) 1918
(C) ** 1939
(D) 1941
EXPLANATIONS BELOW
Concept note-1: -German troops invaded Poland on September 1, 1939, triggering World War II. In response to German aggression, Great Britain and France declared war on Nazi Germany. Nazi Germany possessed overwhelming military superiority over Poland.
Concept note-2: -The “reason” given was that Russia had to come to the aid of its “blood brothers, ” the Ukrainians and Byelorussians, who were trapped in territory that had been illegally annexed by Poland.
Concept note-3: -On September 1, 1939, German forces under the control of Adolf Hitler bombard Poland on land and from the air. World War II had begun.