New inventions/weapons that made World War I an exceptionally deadly conflict included which of the following?

• A. Machine gun, poison gas, tanks, airplanes
• B. Nuclear weapons
• C. Rockets and guided missiles
• D. Swords and bows

Answer: (A)

The main idea is that World War I became exceptionally deadly because industrial-age weapons changed how battles were fought, multiplying casualties and creating new kinds of danger. The machine gun allowed intense, rapid-fire kill zones and contributed to the stalemate of trench warfare, where assaults across open ground were devastating. Poison gas added a terrifying, unpredictable threat that could maim or force rapid defensive changes, increasing the psychological and physical toll of combat. Tanks introduced armored mobility that could break through trenches and cross rough terrain, gradually shifting how armies tried to win battles. Airplanes opened up reconnaissance and later bombing and air combat, expanding the battlefield into the skies and adding another layer of danger and strategic complexity.

Nuclear weapons did not exist during World War I, rockets and guided missiles were not a defining feature of the conflict, and swords and bows belonged to earlier eras. The combination of machine guns, poison gas, tanks, and airplanes best captures the new, deadly technologies that defined World War I.