Question

lincoln steffens was considered a reformer specifically because he
was a journalist.
wrôle about modern issues.
was wealthy and born in the united states.
worked to expose problems in business and in politics.

Explanation:

Lincoln Steffens was a muckraker journalist. Muckrakers aimed to expose corruption and problems in various sectors like business and politics. Just being a journalist (many journalists aren't reformers in this sense), writing about modern issues (vague - could be without a reformist intent), or being wealthy and American - none of these are the core reason for being a reformer. Exposing problems in business and politics aligns with the role of a reformer trying to bring about change.

Answer:

worked to expose problems in business and in politics.