Which of the following historians has organized her study of the past based on the category "period"?
A.A historian writes an extensive text on the important contributions of southeast Asian countries.
B.A historian creates a graph of the economic strength of various empires throughout history. C.A historian assesses a number of primary source documents to create a new secondary source.
D.A historian studies each of the major world powers between the years 100 BCE and 100 CE.

Question

Which of the following historians has organized her study of the past based on the category "period"? 
A.A historian writes an extensive text on the important contributions of southeast Asian countries. 
B.A historian creates a graph of the economic strength of various empires throughout history. C.A historian assesses a number of primary source documents to create a new secondary source. 
D.A historian studies each of the major world powers between the years 100 BCE and 100 CE.