What instrument is utilized to monitor the aircraft’s heading?

The instrument that monitors the aircraft's heading is the magnetic compass. The magnetic compass provides real-time information about the aircraft's direction relative to magnetic north. It is essential for navigation, allowing pilots to maintain the desired flight path by tracking changes in heading.

While other instruments such as the vertical speed indicator, attitude indicator, and glideslope indicator play critical roles in flight operations, they serve different purposes. The vertical speed indicator measures the rate of ascent or descent, the attitude indicator displays the aircraft's orientation relative to the horizon, and the glideslope indicator is used primarily for precise vertical guidance during an approach to landing. None of these instruments directly provide heading information, making the magnetic compass the correct choice for monitoring the aircraft's heading.