Final answer:
The rules to prevent pay to play regarding contributions made to political parties, candidates, and elected officials by firms involved in the underwriting or sales of municipal securities are enforced by the Securities and Exchange Commission (SEC).
Step-by-step explanation:
The rules to prevent pay to play regarding contributions made to political parties, candidates, and elected officials by firms involved in the underwriting or sales of municipal securities are enforced by the Securities and Exchange Commission (SEC). The SEC is responsible for enforcing the federal securities laws and regulations, which includes regulating the activities of firms involved in the underwriting or sales of municipal securities. They ensure compliance with rules that aim to prevent corruption and unfair practices in the financial industry.