An employee can contribute an additional amount to a mayor's re-election campaign without affecting his firm's municipal securities business. What is the maximum amount he can contribute?

In the context of municipal securities business, rules set forth by the Municipal Securities Rulemaking Board (MSRB) provide specific guidelines regarding political contributions made by employees of municipal securities firms. One of the key provisions is that an employee can contribute to the campaign of an official who is responsible for awarding municipal securities business without jeopardizing their firm's ability to conduct business with that official.

The maximum amount an employee may contribute to the campaign of a candidate for mayor, while ensuring that their employer's municipal securities business remains unaffected, is $250. This amount allows employees to participate in the political process while adhering to regulatory boundaries. Contributions exceeding this limit could raise compliance issues and potentially harm the firm's standing in regards to its municipal securities business.

Hence, the correct answer is based on the established parameters set by MSRB concerning allowable contributions without risking the employment's firm's relationship with municipal clients.