And historical _ is a piece of writing would have special significance for an effect on subsequent event .

a) walter looks unhealthy

needs an explanation

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.

i think it may be b, i'm not exactly too sure on this. but b seems to make more sense.