How did farming affect communities in the Americas?

According to ohrp, a problem is an “unanticipated problem” when it meets which of the following criteria: unexpected, related or possibly related to the research, suggests that the research does not put the subjects or others at greater riskunexpected, related or possible related to the research, suggests the research puts subjects or others at greater riskunexpected, unrelated to the research but still occurring with a subject, suggests the research puts others at greater riskexpected, related or possible related to the research, suggests the research puts others at greater risk

Martin, a 32-year-old human relations administrator at a university, believes that all professors over age 50 are incapable of learning the new educational technologies and are content to keep presenting their same "tired, boring" lectures. he often expresses these views to other administrators and does not encourage any of the "older" faculty members to attend professional development meetings related to new teaching approaches nor does he suggest that the university send them to any of the technology conferences. martin is exhibiting

Which of the following items would serve as a primary source for a historian studiying the american civil war