Which of the following is an accepted substitute for the Outer Marker position identification?

The choice of VOR (VHF Omnidirectional Range) as an accepted substitute for the Outer Marker position identification is correct because VORs serve as reliable navigational aids for aircraft. They transmit a VHF radio signal, allowing pilots to determine their position relative to the station. In the context of an approach procedure, a VOR can be used to identify the aircraft's position in relation to the airport and the associated approach path, making it a valid alternative when precise Outer Marker identification is not available.

Other options may not be applicable for various reasons. Inertial navigation relies on internal sensors and can accumulate errors over time, particularly in longer flights, making it less reliable for position identification without external updates. Wi-Fi positioning, while useful in urban areas for civilian navigation, does not provide the necessary accuracy or reliability for traditional aviation operations. Radiosonde data, typically used for meteorological purposes, focuses on atmospheric conditions rather than direct positional information needed for aircraft navigation.