The correct answer is:
c. Moses has those who still believe in God murder the other sinners, and God plagues the survivors.
In the biblical account found in Exodus 32, after the people worship the golden calf, Moses confronts them. He calls upon the Levites to defend God's honor, and they go through the camp striking down those who had sinned. Additionally, God sends a plague as further punishment for the sin of idolatry.