Which statement describes an effect of poisonous gases used in combat during world war i?

a. poisonous gases blistered soldiers’ skin, eyes, and lungs.
b. poisonous gases brought an end to trench warfare.
c. poisonous gases melted weapons and other armaments.
d. poisonous gases caused explosions in the presence of gunpowder.

Correct answer choice is :

Poison gas was applied for the first time at the Second Battle of Ypres in April 1915. As such, all companies in the area were assigned to the firing line of their main right in the path of the chlorine. Its influence was instant and destructive. The French and their Algerian companions retreated in fear.