In the study of history, which is unchanging over time?

A. nothing, because everything can be re-interpreted

B. the available documents for studying a certain period

C. the eras historians choose to highlight

D. the events that are selected as significant

E. the themes used to organize history

In the study of history the available documents for studying a certain period is unchanging over time.

Option: B

Explanation:

History is the study of events and phenomena over space and time. Space means where the particular incident is taking place. Time means the period of occurrence of particular event. A certain period suppose the period of sultanate or mughal empire requires some documents, records to be studied in detail.

And these available documents, records can never be changed over time. History is study of things over changing space and time. Archaeological evidences also keep some valid documents for studying historical events.

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

most people were factory or company owners.