I believe it's "Atlantic slave trade", based on the key words of the quote. Definitely not B or C, it could be A however the quote doesn't really fit it.
Carnival is a holiday that gathers tourists all around the world. They come to enjoy the performance, but also to learn more about the culture of the country, its food, traditions and, of course, while being there, they also share some parts of their own culture. In such a way Carnival enables different nations to become closer and learn more about one another.