Which of the following is considered a secondary source?

Aa news magazine article about migrant farm workers in California
Ba collection of interviews with migrant farm workers
Ca U.S. Department of Agriculture report on farm labor statistics
Da letter written by a migrant farm worker to his family

Verified Answer :

A primary source was created at the time been studied or a short time after. Statistics , Letters and interviews are created/done at the time been studied.  So the magazine article would not be a primary source thus been secondary.

Aa news magazine about migrant farm workers in California
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