Which of the following best describes hypoxia?

Hypoxia refers specifically to a condition where there is a deficiency of oxygen reaching the tissues of the body. In this case, the correct choice highlights low oxygen saturation, which indicates that the body's cells and tissues are not receiving adequate oxygen to function properly. This can lead to various health issues since oxygen is critical for cellular metabolism and energy production.

The concept of hypoxia is particularly relevant in medical settings, where it can result from factors such as respiratory diseases, altitude sickness, or circulatory problems that impair the delivery of oxygen throughout the body. When oxygen saturation levels fall below normal, it signifies that the body is not being adequately oxygenated, thereby leading to potential tissue damage and organ dysfunction if not addressed in a timely manner.