Who provides instructions regarding the removal of oxygen from portable oxygen bottles?

The correct choice is Stat-MD, as this entity is responsible for providing specialized medical advice and protocols, specifically when it comes to emergency situations on board an aircraft, including the administration of oxygen to passengers or crew that may require medical attention. Stat-MD can offer guidance on how to properly utilize portable oxygen bottles to ensure that individuals receive the necessary support in a timely and effective manner.

The other choices involve roles that do not directly specialize in medical protocols or the use of oxygen in emergencies. The Pilot In Command (PIC) is focused on flight operations and safety but may not have the detailed medical training required to give specific instructions on oxygen use. The ground crew primarily deals with aircraft servicing and logistics rather than in-flight medical procedures. Senior cabin crew can provide assistance and operate equipment, but their training focuses more on safety protocols and customer service rather than specific medical instructions related to oxygen use. Thus, Stat-MD stands out as the most appropriate authority for these instructions.