2. Artillery was the deadliest weapon of the war because

The First World War saw many developments in weapons like bomber aircraft, and automatic and portable machine guns, but it was dominated by artillery pieces. Their main aim was to fire explosive-filled projectiles over large distances. Unlike infantry and cavalry, the Artillery could not enter into combat independently on its own. The two main types of artillery used in war were light field Artillery pulled by horses and heavier guns moved by tractors.Field Artillery mainly had cannons with flat trajectories that had calibers ranging from 7.5 to 8.4cm. Heavy artillery also included heavy mortar fire and special guns with calibers of over 30cm that were used for combat against modern armored turret fortifications. The use of artillery increased during wartime and its number was high by the end of the war. Artillery is arguably the most lethal form of land-based armament currently employed, and has been since at least the early Industrial Revolution. The majority of combat deaths in the Napoleonic Wars, World War I, and World War II were caused by artillery. In 1944, Joseph Stalin said in a speech that artillery was "The God of War"

Ithink it’s letter a if i’m not wrong .