The Aztec Empire was a civilization located in western South America (The Andes) And the Spanish invaded the Aztecs and annexed them.
The Berlin Blockade led the conflict between the USSR and
US/Western Allies as this blockade removed the railway access for the western
allies to gain access to the parts in Berlin which were under the control of
the allied forces.
The Declaration of Independence happened in July 4, 1776
I think B is the best answer but I am not sure and I apologize beforehand if it is the incorrect answer.