The first slaves were introduced into the English-American colonies by a Dutch trader, who, in 1619, sold twenty of them to the settlers at Jamestown, Va.
The correct answer is:
B. Relocation to suburbs.
Relocation to suburbs has been a constant of urban life since the early 1900s.
I'm pretty sure A is the secondary source. All of the others come directly from the source/person, but an interview is getting someone else's view.