Which of the following activities could be performed by an unlicensed assistant?

Creating sales brochures is an activity that can be performed by an unlicensed assistant because it involves marketing and organizational tasks that do not require a real estate license. This work typically includes preparing materials that promote a property or a real estate service, which can be done under the supervision of a licensed broker or agent.

In contrast, conducting open houses, negotiating contracts, and showing properties involve activities that directly relate to negotiations and transactions. These tasks require a comprehensive understanding of real estate laws, market conditions, and the specific duties that come with licensed real estate practice, which is why they must be performed by licensed individuals.