What are the primary functions of aircraft pressurization?

The primary functions of aircraft pressurization are fundamentally centered around maintaining a safe and habitable environment for passengers and crew at high altitudes. The correct choice emphasizes the crucial roles in reducing the probability of decompression sickness (DCS) and hypoxia.

As an aircraft ascends to higher altitudes, the atmospheric pressure and availability of oxygen decrease significantly. Pressurization systems create an artificial atmosphere within the cabin, ensuring that even at cruising altitudes, the pressure inside the cabin is much closer to sea-level conditions. This greatly mitigates the risk of hypoxia, which occurs when there isn't enough oxygen available to sustain normal bodily functions. Additionally, it helps prevent DCS, which can happen when there is a rapid reduction in ambient pressure that causes nitrogen dissolved in the body to form bubbles.

While the other choices touch upon benefits that may arise from pressurization, they do not address the primary reason for it. For instance, increased speed and altitude relate more to aircraft design and performance rather than pressurization itself. Improved comfort and cabin noise reduction are secondary effects but do not capture the essential safety aspect of pressurization. Enhanced fuel efficiency and range, while valuable for aircraft operations, also do not fundamentally stem from the process of cabin press