What message indicates distress and the need for assistance?

The message that clearly indicates distress and the need for assistance is "In distress and need assistance." This phrase explicitly communicates an urgent need for help, leaving no ambiguity about the person's situation. In emergency response protocols, such clear and direct language is crucial for alerting rescuers to the seriousness of the predicament.

The other options imply different meanings that do not suggest a need for assistance. "All is well" conveys that everything is fine and does not require any help, while "Safe to land here" indicates that a location is secure for landing, which does not denote distress. "Unable to proceed" could imply some issue, but it does not directly invoke a plea for immediate help or convey an emergency situation as clearly as the chosen option does.