In the study of history, what is one major difference between a region and a period?
A.a region is not influenced by different historical turning points,but a period is.
B.A region can be studied over long spans of time, but a period applies to a specific time span.
C. A region can be studied only in modern era, but a period can be studied in any era.
D.A region can deal with many different themes, but a period deals with one specific theme
