A. slaves should be counted among a state's population for the purpose of deciding the state's number of congressional representatives.
prolly C.
through the introduction of Chinese art and technology
This is a hard one... but I believe it is either C or D. We know that wounded Allied soldiers were a big issue during the war and a big reason as to why the U.S. joined was to gain land and protect its allies that it related to (mainly being Britain). D is also a reasonable answer, but I highly doubt it is the other options. Double check your history book, but I think the answer is C.
Most of them wanted to be neutral but some wanted to side with the Confederates or the Union
Stalin used a multitude of methods to secure power. Regarding what you said he used all of those. He created a secret police to consolidate power, murdered rivals and party members, a one party state to eliminate the democratic process, and finally persecuted Jewish doctors