The correct answer is D) after exiting clear of the helicopter. The reasoning for this is that inflating your life jacket prior to exiting the helicopter could potentially interfere with your ability to safely exit the aircraft. The ideal time to inflate your life jacket is after you have safely exited the helicopter and are clear of the aircraft, in order to avoid any potential hazards or complications during the exit. Inflating the life jacket too early could also potentially cause it to get caught or snagged on the helicopter's interior. The other options are incorrect because A) and B) are too early in the process, before you have fully exited the helicopter, and C) is also too soon, as you want to be clear of the aircraft before inflating the life jacket.