The answer is: Agent.
An agent is a person who is authorized to act on behalf of another person or entity. Agents are typically employed to perform tasks that the principal is unable or unwilling to do themselves. For example, a real estate agent may be hired to sell a property on behalf of the owner, or a stockbroker may be hired to buy and sell stocks on behalf of a client.
Agents are typically bound by a fiduciary duty to their principals. This means that they must act in the best interests of their principals and avoid any conflicts of interest. Agents may also be liable for damages if they breach their duties to their principals.
The other options are incorrect because they do not accurately describe the relationship between an agent and a principal. A lawyer is a person who is qualified to give legal advice and represent clients in court. A broker is a person who acts as an intermediary between buyers and sellers in a transaction. An employee is a person who is hired by another person or entity to perform work under the direction of the employer.