In an effort to try winning World War I, many countries broke previously created treaties and pacts that banned the use of chemical-based weapons.
Based on the excerpt, how did chemical warfare advance during World War I?
a) Allied powers set bundles of wood and sulfur (S) on fire to smoke their enemies out of the trenches.
b) Production of ammonia for fertilizer was re purposed to cause enemies in the trenches to scatter because of the smell it produced.
c) Scientists were forced to stop their research on specific chemicals in order to fight in World War I.
d) Lethal gases, such as chlorine (Cl), were experimented with and used on enemy troops.
d?