Which of the following best describes the system of trench warfare that developed on the western front?

a. digging trenches establish a fast-paced war that favored aggressive tactics.
b. digging trenches eliminate the area on the battlefield known as "no-man's-land."
c. new technologies like machine guns favored defensive tactics and protective trenches.
d. trenches each side mark new positions as the territory on the western front pushed into germany.