Which document is a secondary source about industrialization in the 1800s?

Question

A.
an encyclopedia article about a factory
B.
a photograph taken inside a factory
C.
an account book of factory finances
D.
a journal kept by a factory worker

Answer 1

A. an encyclopedia article about a factory

This is a secondary source because it provides an analysis or interpretation of the topic rather than direct evidence from the time period, unlike the other options which are primary sources.