A syllogism is a kind of logical argument, arriving at a conclusion from the given premises, that is attributed to Artistotle - the correct answer is "a logical sequence created by Aristotle"
About the second question: I would say that it depends on the context. In any case, if you provide some data, it is safe to quote the source - that way noone can accuse you of making it up - so I would go for "quote"
