Final answer:
The MSRB Rule G-37 allows a municipal underwriting manager to contribute up to $250 to a mayoral candidate they can vote for without disqualifying their firm from underwriting municipal bonds for that municipality.
Step-by-step explanation:
Under the Municipal Securities Rulemaking Board (MSRB) rules, specifically Rule G-37, the municipal underwriting manager is permitted to contribute up to $250 to candidates for whom they are entitled to vote without disqualifying their firm from participating as an underwriter in municipal securities business with that issuer.
If the underwriting manager contributes more than that amount, the firm would be disqualified from engaging in underwriting activities with that municipality for a defined period, typically two years from the date of the contribution.