When should a referee stop potentially dangerous holds or maneuvers?

The correct choice is when possible, highlighting that a referee should take action to stop potentially dangerous holds or maneuvers at the earliest opportunity without disrupting the flow of the match excessively. This approach emphasizes the importance of the safety and well-being of the wrestlers. It allows the referee to assess the situation adequately and intervene before any real danger arises, striking a balance between maintaining the integrity of the match and ensuring wrestler safety.

The other options do not establish the best practice. Stopping as soon as they are seen could lead to unnecessary interruptions and affect the match's flow. Waiting until holds become dangerous or only responding to a wrestler's request could put the competitor in harm's way before action is taken. Therefore, stopping a potentially dangerous maneuver when possible ensures proactive protection for the wrestlers involved.