Technological advances in arms and artillery in the era of the civil war resulted in...?

The answer to this question is C. A is not true because forts and defenses were still effective in slowing down cavalry etcetera and were still used. B is false because the confederates had less money and therefore less effective weapons than the union. D is not true because generals did not refuse to use the guns, in fact they were eager to use them. And E is not true because although there were some innovative battle strategies, they did not reduce the likelihood of death as a result of these technological advances.