You read a book called British Columbia at the Turn of the Twentieth Century. While reading it you ...

You read a book called British Columbia at the Turn of the Twentieth Century. While reading it you notice that the author discusses only the lives and ideas of five individuals based upon their diaries. The author avoids making any sort of generalizations or integrating some possible themes. What problem with secondary sources is illustrated with this example?
A) Historians often use vague concepts with inconsistent definitions to organize the primary sources they read.
B) Historians select a tiny fraction of the mass of information they read, but the selection process is largely unseen and unknown.
C) Historians often have to rely recollections that are distorted by the imperfections of memory.
D) Historians, especially those who write in a narrative form, separate out significant from trivial information, but rarely make their social theories explicit.
E) Historians are influenced by various “schools” of historiography.