To explain the Great Atlantic Migration, the most fitting response would be economic push factors in Europe resulting from crop failures and political push factors in Europe due to governmental instability. These factors often compel individuals to leave their home countries in search of better opportunities.
However, if you need to choose only one response that forms a comprehensive theory, the economic push factors in Europe resulting from crop failures would be most significant as it captures the economic hardships that drove many to migrate.
Would you like further elaboration on any of these factors?