I think it is A B and C, but I am not completely sure, it might be B, C, and D.
The event that led to defeat at Waterloo was:
B.a Russian army strikes the final blow at the battle of Waterloo
Explanation:
The Russian army's final strike at Waterloo against the immortal guards of Napoleon which were supposed to be the old guard that never fell and then they were routed from the war leaving Napoleon himself defenseless.
This route was the final blow at the end of Waterloo's battle dealt by the Russians against Napoleon's forces and it resulted in an utter defeat on his side which Napoleon has rarely seen in his life's entire campaigns.
The Pacific Railroad<span> Act chartered the Central Pacific and the Union Pacific </span>Railroad<span>Companies, and tasked them with building a </span>transcontinental railroad<span> that would link the United States from east to west. ... This affected the Native Americans in a negative way because the Native Americans used buffalo for many things.</span>
