Christianity is the correct answer :)
The correct answer is D i believe <span />
The blockade was supposed to prevent the South from getting resources and support from other countries who would support it such as those in Europe who were ready to recognize it as independent and help it if it meant that in the long run it would help them by weakening the Union.
I think its A. The US always trifle in worldly affairs of others mostly if it benefits the US for more support.