Why Does the Self-Interest of Protectionist Groups Increase the Effectiveness

Why does the self-interest of protectionist groups increase the effectiveness of RTAs in enforcing human rights law?

A) Protectionist groups would prefer to have free-trade agreements revoked,which makes them more vigilant in examining the human rights records of other member states.
B) Since protectionist groups approve of free-trade agreements only with democratic states,their governments tend to sign treaties with states that already have good human rights records.
C) Protectionist groups want trade agreements to succeed,so they advocate for more aid to help other countries avoid human rights abuses that would jeopardize their trading status.
D) Protectionist unions promote free-trade agreements so that other countries will become wealthier,which will lead to greater democracy and thus better political conditions for their fellow workers.