During World War I, the zigzag pattern of trenches on the front lines was designed to provide a place from which to fire on the enemy.
supply soldiers with a place to store weapons.
protect troops from enemy fire.
shield machine guns from enemy attack.

C -Protect troops from enemy fire

During world war 1, the zigzag pattern of trenches on the front lines was designed to protect troops from enemy fire. The trenches were dug in a zigzag pattern instead of the usual straight pattern. In World War I, trenches were built in zigzag pattern with many different levels along the lines. In order to make sure there is movement for the soldiers, paths were dug between these levels.

must repent and believe in god.

or the book

journey across time - chapter 10 "the rise of christianity"