Final answer:
The MSRB pay-to-play rule prohibits a municipal finance professional from making a contribution to the campaign for a friend running for state legislative district. Correct option is b.
Step-by-step explanation:
According to the MSRB pay-to-play rule, a municipal finance professional (MFP) cannot make a contribution to the campaign for a friend running to represent the state legislative district that the MFP resides in. Therefore, the correct answer is b) is prohibited. The MSRB pay-to-play rule places limits on campaign contributions to maintain a more equal playing field for candidates and prevent potential conflicts of interest.