Select the correct answer. Which best describes the way photographs are considered by historlans?
A. primary source documents that are useful in the study of history
B. reliable sources for the study of history only if from a named source
C. secondary source documents that are useful in the study of history
D. unrellable sources for the study of history because they are too subjectivve
E. useful sources for the study of personal historles, but not for general history ​