In the context of a Minimum Operating Network (MON) at an airport, what is the procedure regarding Instrument Landing System (ILS) or Very High-Frequency Omnidirectional Range (VOR) approach procedures in the event of a RNAV (Area Navigation) outage?

A) They are suspended indefinitely.
B) They are not affected by RNAV outages.
C) They will be retained for use during RNAV outages.
D) They are replaced with alternative navigation methods.