Which of the following can unlicensed assistants NOT do?

Unlicensed assistants are prohibited from showing properties due to legal regulations surrounding real estate transactions. This restriction is in place because showing properties involves a level of expertise and responsibility that is reserved for licensed real estate professionals. Licensed agents are trained to represent clients, provide information about the properties, and answer questions that require knowledge of real estate laws and practices.

In contrast, tasks such as answering phones, scheduling appointments, and typing correspondence do not require a real estate license. These activities are considered administrative and support roles that help licensed agents in their work, making them allowable functions for unlicensed personnel. Thus, showing properties is clearly delineated as an activity that must be performed by a licensed individual, making it the correct choice in this context.