Answer:
O A. Trenches were used extensively in World War I.
Explanation:
Trenches are long and narrow pathways dug out to allow the passage or movement of soldiers during wars. They are dug out as hiding places, movement from one side to another while also helping in shielding the soldiers from enemy fire.
In the soldier's letter to his mother, he describes how the <em>"trenches stretch for miles"</em>. And even though they cover miles of land, they (soldiers) are unable to move in fear of being shot at. This is why they must be alert and be patient, or they will get shot at any time they make any movement.
The <u>statement that best represents the main idea of this source seems to be that trenches were used extensively during the First World War.</u>
Thus, the correct answer is option A.
