What do scientists need to look at before developing an argument? O The validity of data, claims, hypotheses, and observations.
O Their opinion and personal views.
O The arguments of famous people on the topic.
O The arguments that make the most sense for society.

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years