Modern weapons (les) combined outdated tactics are one explanation for the high number of casualties is true regarding the Civil War.
Option c
Explanation:
The number of people who died during the civil is approximately 620,000 and the war is normally called the first modern war due to advance technology employed. Weapons used were firearms, rifled-muskets, repeating weapons, breech loaders, field guns, new weapons machine guns and grenades.
Introduction of advanced war tactics during the Civil war introduced mass production, gun barrels, Minie ball metallic cartridges ironclad warships. There was also an advanced method of communication medicines and transportation. It should be noted that the death toll also included people who died due to illnesses and not only who died in the battle.