DNA what did scientist learn about Black Death

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

Which of the following best summarizes the idea represented by this graph?

3. explain one example of how the u.s. has struggled to balance energy independence and environmentalprotection