Alexander the Great's Conquests in Asia Occurred Despite

Alexander the Great's conquests in Asia occurred despite

A) his having no military expertise prior to his father's assassination.
B) the Persian king Darius III's refusal to make any peace settlements and resort to guerilla warfare.
C) the lack of a strong cavalry and inability to capture Egypt.
D) his eventual difficulties in convincing his troops to fight so far from home.
E) violent opposition back in Greece by most of the city-states.