Final answer:
The O2 requirement for cabin pressure altitudes 12,500-14,000ft is higher due to decreased oxygen levels. The exact requirement varies depending on individual factors.
Step-by-step explanation:
When the cabin pressure altitudes are between 12,500 and 14,000 feet, the O2 requirement is higher due to the lower air density and decreased oxygen levels at higher altitudes. At these altitudes, the partial pressure of oxygen decreases, making it necessary to provide supplemental oxygen. The exact O2 requirement for cabin pressure altitudes in this range will vary depending on factors such as the individual's health and age.