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.

explanation:

there are two statements that are incorrect.

1. the marshall plan was a lend lease program. it was an economic plan that europe redevelop itself after wwii.

2. einstein didn't really do anything to further the allied cause in building the bomb. he merely sent a letter to fdr telling him (in 1939) that if the united states entered the war, perhaps it would be wise to build the bomb before germany did. i would say this answer is incorrect, but when america entered the war 2 years later, fdr thought it might be a good idea to take einstein's advice.

the 4th choice is definitely so wrong that is likely the single answer of this question

the answers are 1 and 4