Please help, I really need this

Ahistorian is writing a book about british prime minister winston churchill. she claims that churchill was one of the earliest british leaders to realize that nazi germany was a serious threat to british security what is the best way to determine whether the historian's interpretation is valid? o a. review primary sources to see if churchill ever recorded his opinions of nazi germany. o b. find out whether the historian has written any other books about british leaders. c. analyze secondary sources summarizing the effects of nazi germany on great britain. o d. cite the historian's book in another study about important 20th- century world leaders.

Read a report of the paris medical faculty from 1348 about the plague. we can say that the main cause of this pestilence was and is the configuration of the heavens. in 1345, at 1: 00 in the afternoon of march 20th, there was a major conjunction of three planets in the constellation of aquarius. this conjunction, along with others like it and the eclipse caused a deadly corruption of the air around us. what is the most likely reason this document would be important to a historian’s study of the black death? a) it shows the importance of astronomy in medicine today. b) it shows how medicine once differed in paris and london. c) it shows how the plague’s cause was interpreted in the past. d) it shows the desperation to find a cause of the black death.

Ahistorian who compares the expansion of political systems to the expansion of economic systems is organizing history by