Which statement correctly matches the MK 25 UBA's relaxed and high-exercise consumption rates?

• A. 1.3 L/min for a high exercise rate and 2 L/min for a relaxed pace
• B. 2 L/min for a relaxed pace and 1.3 L/min for a high exercise
• C. 2.5 L/min for both paces
• D. 1.3 L/min for a relaxed pace; 2 L/min for a high exercise rate

Answer: (D)

Breathing gas use rises with how hard you work. When you're relaxed, you inhale less air per minute; during high exercise, your breathing rate and depth increase, so you consume more gas. For the MK 25 UBA, the published figures reflect about 1.3 liters per minute at a relaxed pace and about 2 liters per minute at high exercise. This pairing is the best because it matches the device’s documented consumption pattern and is what you’d use to plan gas duration and bailout needs. Other options either swap the rates or use the same rate for both paces, which doesn’t align with how breathing demand changes with exertion.