Explanation: F1B ARQ (Automatic Repeat reQuest) is a synchronous data mode where stations alternate between transmitting and receiving. During its transmit phase, an ARQ station will send blocks of data or idle signals. When it's its turn to receive an acknowledgment or data from the other station, it switches to receive mode. F1B is a type of FSK (Frequency Shift Keying), which is a constant envelope modulation. This means that when the transmitter is keyed on, it outputs a constant RF power, in this case, up to 150 watts. However, due to the ARQ protocol's transmit/receive cycling, the transmitter is not continuously keyed. It keys on for its transmit period (outputting 150 watts) and then keys off for its receive period (outputting 0 watts). Therefore, the RF power meter will show the output fluctuating between 0 and 150 watts. Option A is incorrect because ARQ operation involves transmit/receive cycles, so the output is not constant. Option B is incorrect as ARQ also transmits idle signals and control information, not just typed characters. Option C is incorrect because an RF "S" meter measures *received* signal strength, not transmitted power output.