I have taken this before and I believe the answer is D
The correct answer is letter A.
Interest groups are primarily focused on actively promoting a particular cause or belief. They are usually composed of voluntary associations that publicly promote and create advantage for their specific cause. Charitable groups, trade associations, and civil rights groups are some examples of interest groups in society.
The correct answer is: B. The increase in the labor unions' political power
Labor Unions were on the rise during the Progressive Era and this enabled Debs, a socialist, to come to power.