Answer:
A simply because its the only one I think seems right!
I think its because that preast guy dies.
I'd say d is the answer. By chemical attack, it is specifically a gas attack. Gas masks, all buy one is able to put on their gas masks. Presumably that one guy died. B is definitely incorrect.
Condensing a longer text into a brief synopsis of its main points is B) summarizing.
When you summarize, you are trying to shorten the text as much as possible, but keep the original idea and theme intact. You just want to explain what is happening in your own words.
Technically this has two answers. Peasants did not socialize with members of the upper class and therefore high society would not have been introduced to the dance until later in the century. However, the real true answer is because the dance was considered to be too bad mannered for refined people. Those of high society had their own dances and would almost never do anything that lower class people would do, but with this dance it was different. The dance required the couple to face each other in a closed position and they had to physically touch for the entire dance. This was simply not allowed for the elite because it was scandalous that unwedded men and women would ever be in such a position to resemble an intimate embrace.