What does it mean to call someone a “benedict arnold”?

Which statements describe how reformers fought for social change in the progressive era? check all that apply. 1. they founded a state university to promote industrialization. 2. they began a civil rights movement to promote equality between races. 3. they made it legal to manufacture and sell alcohol. 4. they built thousands of new schools and required attendance. 5. they promoted abstinence from alcohol and supported prohibition.