In Areas Where the Military Momentum Was Lost, All of the Following

In areas where the military momentum was lost, all of the following happened except

A) early and frequent mutinies.
B) armies dug extensive trench systems defended by barbed wire and machine guns.
C) each side mounted increasingly large and costly land attacks.
D) a war of attrition ensued.
E) trenches became filthy, foul vermin ridden networks for millions of soldiers.