What are the most common signs of oxygen toxicity?

The most common signs of oxygen toxicity relate to the effects of elevated partial pressures of oxygen on the central nervous system. Visual disturbances may include blurred vision, tunnel vision, or other sight changes, which can significantly impact a diver's ability to navigate underwater environments. Ringing in the ears, or tinnitus, is another common sensory disruption that can occur, signaling nervous system involvement. Muscular twitching often represents neurological irritation and can lead to more severe symptoms if the exposure continues.

These symptoms primarily reflect the impact of high oxygen levels on the nervous system, which can become problematic during dives with enriched air mixtures, particularly at greater depths. Recognizing these signs is crucial for divers, as they indicate the need for immediate action to reduce oxygen exposure and prevent more serious consequences associated with toxicity.

While dizziness, shortness of breath, and increased heart rate, nausea, headaches, fatigue, and loss of consciousness are concerning symptoms, they are not as specifically associated with oxygen toxicity as the signs identified in the correct answer. Hence, option B accurately portrays the hallmark symptoms indicative of this condition, reinforcing the need for divers to be vigilant about their oxygen exposure.