The battle at Lexington and Concord shaped the american revolution through it was the first victory and battle of the revolution so in this it brought more people to the american cause seeing that their militia were able to take on the world power of Britain and succeed in doing so.
The congress of Vienna was supposed to ensure future disputes would be settled in a manner that would avoid the terrible wars of the previous twenty years.
Ford pardoned Nixon for any crimes he may have committed as president. The presidential pardon meant that Nixon would never have to face criminal charges over his involvement in the Watergate scandal.
I believe the answer is C.
