Which navigation system helps pilots navigate and land at selected airfields, utilizing ILS functions?

The VHF Navigation (ILS) system is indeed the correct answer because Instrument Landing System (ILS) is a precision runway approach system that provides guidance to aircraft for landing. It does this by utilizing radio signals to direct pilots along a defined flight path, providing both lateral (horizontal) and vertical (vertical) guidance.

When using ILS, pilots can receive accurate positioning information, which is crucial during low visibility conditions such as fog or heavy rain. The system broadcasts two radio beams: one for lateral position (localizer) and another for vertical guidance (glideslope), allowing the aircraft to align with the runway and descend to the runway threshold safely.

Other systems listed have their specific functions but do not provide the same level of precision and capability for landing as the ILS. The Global Positioning System (GPS), while excellent for general navigation, does not inherently function as an approach system like ILS. The Tactical Air Navigation System (TACAN) is primarily a military navigation aid that provides range and bearing but lacks the precise landing guidance offered by ILS. Marker beacons are used to signal specific locations along an approach but do not provide the continuous guidance necessary for landing. Thus, the ILS specifically addresses the need for directed approach and