Which frequency should pilots monitor for engine startup advisories?

Pilots should monitor Ground Control frequency for engine startup advisories because this frequency is used for communication regarding all ground operations at an airport. Ground Control provides vital instructions and information needed for taxiing, engine starts, and other pre-flight procedures while the aircraft is still on the ground. Monitoring this frequency ensures pilots receive the necessary clearances or advisories related to commencing engine operations.

The other options relate to different phases of flight or functions within air traffic control. Departure Control focuses on managing aircraft once they are airborne, while ATIS (Automatic Terminal Information Service) provides essential information about the airport conditions, such as weather and active runways, but does not specifically give advisories for engine starts. Clearance Control, on the other hand, is responsible for issuing the initial clearance before departure but does not oversee the engine startup process. Thus, Ground Control is the most appropriate frequency for engine startup advisories.