The correct answer is A) greater than outside air pressure. When an enclosed lifeboat has the air supply turned on, the air pressure inside the lifeboat will be greater than the outside air pressure. This is because the air supply system is actively pumping air into the enclosed space, which increases the internal pressure to maintain a safe and breathable atmosphere for the occupants. The increased internal pressure ensures that air can flow outward through any openings, preventing the ingress of water or toxic gases from outside. The other options are incorrect because: B) the internal air pressure is not affected by the speed of the craft, C) the internal pressure is not equal to the outside pressure, and D) the internal pressure is greater, not less, than the outside pressure.