Explanation: To safely and effectively evaluate a marine VHF transmitter with a spectrum analyzer (SPECAN), proper power management is crucial. A marine VHF transmitter can output up to 25 watts, which is far too much power for a typical SPECAN's sensitive input, potentially causing severe damage. The best procedure involves: 1. **Connecting through an in-line attenuator:** This device reduces the signal power to a level safe for the SPECAN's input. 2. **Applying maximum attenuation:** Always start with maximum attenuation. This provides the highest level of protection for the SPECAN, preventing damage from an unknown or excessive signal level. Once a signal is observed, attenuation can be carefully reduced if needed to get a better display. 3. **Switching the transmitter:** The missing part of the option likely refers to keying the transmitter or turning it on to generate the signal for analysis. Options A and B share the correct initial steps regarding the attenuator and maximum attenuation. However, option C is incorrect because applying *minimum* attenuation would expose the SPECAN to high power levels from the transmitter, risking immediate damage. Option D, by specifying "maximum attenuation," ensures the safety of the sensitive spectrum analyzer while preparing to evaluate the transmitter's output.