Which of these is a person who is licensed to represent one of the parties in a real estate transaction in exchange for a commission or other valuable consideration?

An assistant broker typically holds a broker's license but assists a managing broker rather than directly representing clients. Their role is more administrative or supportive, focusing on specific tasks rather than engaging in transactions independently. Thus, they do not directly earn commissions from transactions like a salesperson would.

An appraiser is a professional who assesses the value of real estate properties, providing important information for buyers, sellers, and lenders. However, they do not represent clients in transactions and do not earn commissions from sales. Their role is purely evaluative and does not involve negotiation or facilitation of real estate deals.

A broker is a licensed professional who can operate independently and manage real estate transactions, often overseeing salespersons. While brokers can directly represent clients, the question specifically asks for a person who represents parties in exchange for a commission, which aligns more closely with the role of a salesperson operating under a broker's supervision.