Which of the following statements is true?

Correct Answer: Option B — The GMDSS Radio Operator can program the NAVTEX receiver to reject all messages except navigation warnings, meteorological warnings, and search and rescue information.

IMO regulations mandate that certain critical message categories, specifically navigational warnings, meteorological warnings, and search and rescue information, cannot be rejected by the operator. This ensures that essential safety information is always received, regardless of the operator's settings, maintaining the integrity of the GMDSS safety net.