Answer:
D.
Step-by-step explanation:
European armies' increasing reliance on railways culminated in one of the world's bloodiest wars. ... In Vienna, then Berlin, then Paris, similar telegraphs clattered. ... In all, nearly 200,000 troops and 55,000 horses rode the rails to the front. ... Unlike the German lines, four-fifths of the French rail network was double-tracked, ... HOPE YA GET IT! :D