Which of the following is a symptom of mild hypoxia?

Mild hypoxia refers to a condition where there is a slight deficiency in the oxygen supply to the tissues, which can lead to various physiological responses without severe impairment. Yawning is often linked to mild hypoxia, as it is a reflex action that may occur in an attempt to increase oxygen intake and alertness.

When the body senses reduced oxygen levels, yawning can help facilitate deeper inhalations, thus potentially alleviating the sensation of fatigue or drowsiness associated with mild hypoxia. This response is typically less concerning than the symptoms associated with more severe forms of hypoxia, which can lead to more drastic symptoms like loss of muscular coordination, convulsions, or even death if left unaddressed.

Therefore, yawning is a symptom that is consistent with mild hypoxia, making it the most appropriate choice in this context.