During World War I,the New Technology of Warfare

During World War I,the new technology of warfare

A) created logistical problems that slowed many offensives.
B) allowed the attack of the enemy without direct combat.
C) were largely responsible for the appalling level of casualties.
D) both created logistical problems that slowed many offensives,and allowed the attack of the enemy without direct combat.
E) All these answers are correct.