A Unique Aspect of the Western Front Was

A unique aspect of the Western Front was

A) that only swords were "legal," so no guns were used.
B) the stalemate that ensued for three years along a three-hundred-mile-long line of armies from Switzerland to the North Sea.
C) that women made up a small percentage of the German fighting force.
D) that there was very little loss of life.
E) the German use of "blitzkrieg" on the battlefield.