Answer: 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.