What items are heated when selecting the PROBES pushbutton annunciator ON?

When the PROBES pushbutton annunciator is selected to the ON position, it activates heating elements that target specific parts of the aircraft's system to ensure they function correctly. The correct choice indicates that the heating system includes the Pitot static probes, static ports, and the Total Air Temperature (TAT) probe.

The inclusion of both the Pitot static probes and static ports is essential because these components are critical for measuring airspeed and altitude. Keeping these areas ice-free is vital for accurate readings, especially in cold weather conditions. Additionally, the TAT probe is included because accurate air temperature readings are also critical for various systems, including those affecting engine performance and aerodynamic calculations.

The other options do not fully encompass the components that require heating to ensure safety and performance, leaving critical instruments unprotected against the effects of icing, which can lead to erroneous readings or system failures.