What must be true about Nathan's situation when he assisted with purchasing a commercial building without holding a real estate license?

In the context of real estate transactions, individuals typically need to be licensed to represent others in the purchase or sale of property. However, there are specific exemptions outlined in real estate laws. When considering Nathan's situation, the option indicating that he is a public official whose salaried duties include real estate transactions is valid because certain public officials, such as government employees or officials who deal with real estate as part of their job, may perform real estate-related activities without needing a real estate license. This exemption is crucial, as it allows him to assist with the purchase of a commercial building while adhering to the regulations that govern real estate practices.

The other options suggest circumstances that would not apply to Nathan. For instance, being a licensed real estate agent or acting on behalf of a licensed broker would require specific credentials that Nathan does not possess. Additionally, being exempt from licensing laws applies generally to a narrower set of conditions than those mentioned, making B the only fitting choice in this scenario.