Final answer:
Authorized DME or VOR fixes can be substituted for an inoperative outer marker.
Step-by-step explanation:
An inoperative outer marker is a navigational aid used in aviation to provide pilots with precise information about their position during approach and landing.
If an outer marker becomes inoperative, it can be substituted with authorized DME or VOR fixes. Distance Measuring Equipment (DME) and VOR (VHF Omnidirectional Range) are other types of navigational aids that can provide pilots with similar information about their position.
Therefore, option A) authorized DME or VOR fixes can be substituted for an inoperative outer marker.