If I remember correct, it is B. Provision of a fugitive slave act.
I think that the answer is D, to create railroad networks that spanned the entire country
There is not a specific antonym for diaspora, but the opposite of a diaspora would be the regrouping of a community or the coming together of a community. It could also be a renewal of a specific cultural group or ethnicity coming back together in a sort of revival of their culture.
Answer:
Memorial Day commemorated soldiers killed in World War I
