In an altitude system, which component is used to display altitude in relation to sea level?

The correct choice indicates that the altimeter setting is the component used to display altitude in relation to sea level. The altimeter setting refers to the barometric pressure at sea level that is entered into the altimeter. By adjusting the altimeter to this setting, the instrument can accurately reflect the aircraft's altitude above sea level, which is crucial for navigation and maintaining vertical separation from terrain and other aircraft.

When the altimeter is set correctly to the current local altimeter setting—usually provided by air traffic control or meteorological services—it compensates for changes in atmospheric pressure, ensuring that the altitude reading is accurate relative to that standard reference of sea level. This allows pilots to make informed decisions regarding their altitude in relation to the surrounding environment.

Other options, while related, do not specifically address the component that displays altitude relative to sea level. For example, an absolute altimeter measures the actual height above ground level, not sea level. An adjustable altimeter refers to the capability of the altimeter to be set to different pressures but does not itself define the altitude display. Lastly, a standard altimeter typically refers to an instrument that reads altitude based on the standard atmospheric pressure at sea level (29.92 inches of mercury), but without the context of the