What component allows control of the altimeter setting displayed on the Primary Flight Display?

The component that allows control of the altimeter setting displayed on the Primary Flight Display (PFD) is indeed the EFIS Control Panels. These panels are crucial for pilots as they provide the means to adjust and configure the information displayed on the PFD, including the altimeter settings.

When a pilot adjusts the altimeter setting through the EFIS Control Panel, this change is reflected on the PFD, ensuring that altitude information is accurate for flight operations. This functionality is vital for maintaining proper situational awareness, especially during takeoff, landing, and while flying at various flight levels.

The other components mentioned, such as the Flight Control Unit, Master Caution/Warning Lights, and Standby Flight Instruments, serve different roles. The Flight Control Unit is primarily responsible for managing autopilot functions, while the Master Caution/Warning Lights indicate various system statuses but do not provide direct control over altimeter settings. Standby Flight Instruments serve as backup indicators in case of primary system failure, but they do not offer the adjustments to altimeter settings that the EFIS Control Panel does. Thus, understanding the specific functions and operations of each component is essential for effective use of the aircraft's systems, particularly in managing altitude accurately during flight.