What is an important rule regarding breath control while ascending?

Exhaling continuously while ascending is crucial for maintaining safe breath control during a dive. As a diver ascends, the pressure surrounding their body decreases. If a diver holds their breath during this ascent, the expanding air in the lungs can lead to serious injuries, such as lung over-expansion or even an embolism. By exhaling continuously, the diver allows the air in their lungs to expand safely, preventing dangerous pressure buildup. This practice not only enhances the diver's safety but also helps in regulating buoyancy and maintaining control during the ascent.

Other options miss the critical principle of maintaining pressure equilibrium within the lungs. Holding the breath can cause severe consequences, and inhaling deeply at depth does not aid in safe ascent as it can contribute to holding in air. Slowly releasing air may provide some temporary relief, but continuous exhalation is the best approach during ascent for safety and effectiveness.