The correct answer is D) after exiting clear of the helicopter. The reasoning for this is that inflating your life jacket while still inside the helicopter could inadvertently cause problems during the emergency landing on the water. The life jacket could become snagged or interfere with your ability to move inside the confined space. The best practice is to wait until you have safely exited the helicopter and are clear of the aircraft before inflating your life jacket. This ensures your mobility is not restricted during the emergency procedures and you can safely access the water while properly protected by the inflated life jacket. The other options are incorrect because inflating the life jacket too early (A and B) could create safety issues, while inflating it after exiting the helicopter but before clearing it (C) would still pose potential entanglement risks.