Which of the following references should the GMDSS Radio Operator consult for information on the proper operation of equipment?

Correct Answer: Option B — The manufacturer's operator manuals.

Manufacturer operator manuals are the primary technical references for the specific interface, menu navigation, and operational features of installed GMDSS equipment. While regulations define what equipment is required, the specific steps to initiate a DSC distress alert or perform a self-test are unique to each manufacturer's hardware design.