Final answer:
In the event of an aircraft cabin hull rupture, oxygen masks will automatically deploy to ensure passengers can continue to breathe, as the cabin pressure will decrease.
Step-by-step explanation:
If the aircraft cabin experiences a hull rupture, the immediate concern will be the loss of cabin pressurization. In this scenario, the correct answer is c) Oxygen masks will automatically deploy. The drop in cabin pressure will trigger the release of oxygen masks for passengers to use. Air pressure will definitely be affected; it will not remain the same (option b) and air supply will not increase to compensate (option d), as the pressurization system is compromised. There will still be air to breathe, so option a) is not entirely accurate, but the availability of breathable air (oxygen) at high altitudes without supplemental oxygen will be limited.
Oxygen masks are designed to deploy automatically when the cabin pressure falls below a certain level. This safety feature ensures that passengers can continue to breathe even if the pressurization system fails due to a hull rupture or any other reason. The masks provide a flow of oxygen from pre-filled cylinders, allowing passengers to breathe normally until the pilot can initiate an emergency descent to a safer, breathable altitude.