The OAS or the Organization of American States is an organization that was founded in 1948 that seeks to maintain peaceful alliances and cooperation amongst the nations of North and South America.
The correct answer for this question is letter "D) a series of military victories against Austria."
These are the following choices:
A) disruption of British trade with India
B) the spread of nationalism in Europe
C) the defeat of the British at Trafalgar
D) a series of military victories against Austria