The correct answer is D: The class of operator license held by the control operator. According to FCC Part 97.301, the control operator's license class determines the transmitting frequency privileges of an amateur station. The station can operate on any frequency where the control operator has privileges, regardless of the station licensee's license class. This is a fundamental principle: the control operator's privileges determine what frequencies the station can use. If a Technician is the control operator, the station has Technician privileges. If a General class operator is controlling, the station has General privileges. The station licensee's license class doesn't matter - it's the control operator's class that counts. This allows stations to be operated by different license classes at different times, with privileges changing based on who's controlling.