What references should be consulted for proper range markings for aircraft instruments?

The correct choice emphasizes the importance of consulting the aircraft maintenance manual and specifications when determining the proper range markings for aircraft instruments. The aircraft maintenance manual provides detailed information about the aircraft systems, including the specifications and tolerances required for various instruments. These documents outline the correct operational parameters, which are crucial for ensuring that the instruments function correctly and that proper safety margins are maintained.

Additionally, relying solely on the pilot's operating handbook, FAA regulations, or industry standards would not provide the comprehensive and specific information contained within the maintenance manual. While those resources can offer valuable insights, they may not detail the instrument ranges pertinent to each specific aircraft model. Therefore, to ensure accurate and safe operation of the aircraft, it's critical to refer to the aircraft maintenance manual as well as any relevant specifications.