How does the author MAINLY explain what segregation is? (A) by giving examples of what happened to Freedom Ride buses
(B) by describing different court decisions about bus seating
(C) by describing who rode on the Freedom Ride buses
(D) by giving examples of separate facilities for whites and blacks

well stockyards mean a large yard containing pens and sheds, typically adjacent to a slaughterhouse, in which livestock is kept and sorted. and i'm assuming that by party you   mean a large group of people which does make sense because chicago is a very crowded place much like new york. stockyards tend to take up a lot of room due to needing the area for pens to keep animals in and the fact that stockyards are usually right by slaughterhouse where they process and distribute the product. so its much like a zoo but with some dead animal products close by.