Europeans didn't use maritime routes before the age of exploration because they feared that the muslims controlling Portugal and Spain made maritime routes unsafe together with the fact that they didn't have the required ships and navigations skills to travel around Africa to Asia.
The fall of the Aztecs is due to their treatment of others and neighboring civilizations. Hope this helps :)
"The law states that all male US citizens and male immigrant non-citizens are required by law if they are between the ages of 18 and 25, to register in at least 30 days after their 18th birthday."
A civil war between the Taira and Minamoto clans.
If I remember right it would be B