The correct answer is B. Germany's constant fear in the 19th and 20th centuries was the threat of a two-front war against France and Russia.
Towards the end of the 19th century, Europe was a territory convulsed by constant confrontation between the great powers. The Russian expansionism, on the one hand, and the constant tensions with France, on the other, caused the German Empire to see the need to rearm after the unification in 1871.
The army became a central element of emerging imperial patriotism. Criticism of the military was seen as unpatriotic. During this period the Schlieffen concept emerged for a possible war on two fronts against France and Russia, and the armed forces were reinforced in the face of such a hypothesis.
