Due to the deaths of most of the population, "ordinary farm workers, who had been forced into serfdom previously, shot up by 50%. More bullion among a smaller population meant more wealth across all classes and because the same land was in use and it was now plentiful, it resulted in technological advances as well." - Hank Campbell (found at Science20.com)
About a third of the clergy fell to the Black Death, making answer a. unlikely.
I never found any information stating Peasants migrated into cities for medical care, making answer b. unlikely.
Lower classes benefited from the Black Death economically, therefore c. is my final answer.
Doctors at this time knew nothing about how to cure disease, they also made little to none advancements. Answer d. is very wrong.
If I am not mistaken, it was the space program also know as the Apollo Program a.k.a Project Apollo
Johannes Gutenburg created the printing press during the renaissance. It was important because it made the mass production of printed materials possible. It also lead to a much wider dissemination of knowledge and literacy throughout the socioeconomics classes.
Answer: C: Chicago police attacked a peacful demonstrations E: this called for a labor protest meeting.
C: An unknown person threw a bomb at police
E: It turned it into the hat market riot.
Explanation: