Which bearing indicators provide magnetic bearings from ADF and VOR sources?

The Radio Magnetic Indicator (RMI) is designed specifically to provide pilots with magnetic bearings from both Automatic Direction Finder (ADF) and VOR sources. The RMI typically displays one or two pointers, with one pointer indicating ADF signals and the other indicating VOR radial information. This dual functionality is integral for navigation, as it allows pilots to determine their bearing to a navigational aid, simplifying situational awareness.

Unlike the RMI, a Heading Indicator (HI) primarily displays the aircraft's current heading, providing no direct information about navigational aids. The Horizontal Situational Indicator (HSI) combines heading and navigational information but does so differently; it typically integrates both VOR and localizer information into a single display, which can be more complex than the straightforward indication given by an RMI.

The Affiliated Direction Finder (ADF) itself is a type of navigational aid providing relative bearings but does not display magnetic bearings in the same manner as an RMI, nor does it combine VOR and ADF information in a single interface. Therefore, the RMI stands out as the correct answer for its ability to directly indicate magnetic bearings from both ADF and VOR sources.