They came first for the Communists , and I did n't speak up because I was n't a Communist . Then they came for the Jews , and I did n't speak up because I was n't a Jew . Then they came for the trade unionists , and I did n't speak up because I was n't a trade unionist . Then they came for the Catholics , and I did n't speak up because I was a Protestant .
According to the above context, choose the best option to answer the following question.
Question: What is the purpose of the post ?
Options:
- None of the above choices .
 - To teach history
 - To teach literature
 - To teach economics


To teach history