Answer:
C. Columbus did not reach the mainland of the new world until his third voyage
Explanation:
The fact that the Spanish people with Colombus leading them didn´t reach mainland in america up untill their third trip, explains essencially why the power of Spain over the new world took time, it was so large and so far away that they had problems exploring and conquering all of it. Eventually they were able to conquer and start exploiting the natural resources in America, but this took them over 40 years.