Question

Which of the following was an effective weapon in WWI because the vapors given off caused burning, swelling of nose, throat, and eyes, and often death?

Answer 1

The most effective weapons were poisonous gasses. The example that you gave will be the mustard gas, which was commonly used by both sides during the war. These weapons were so effective to the point they were banned from being used after the war.

hope this helps :D