An Example of Primary Historical Evidence on the 1930s Depression

An example of primary historical evidence on the 1930s Depression decade is

A) an article in last month's Time magazine on the Depression diet
B) a book written in 1953 titled The Depression Years in America
C) a film starring Katherine Hepburn made in 1936
D) a letter written by my mother and sent to me two years ago telling me what she experienced growing up in the Depression period