Which of the following is a symptom of hypoxia in diving?

Hypoxia, which occurs when there is a deficiency of oxygen in the body, can manifest through a variety of symptoms, all of which can raise serious concerns for divers. Unconsciousness is an extreme and alarming symptom that indicates a critical lack of oxygen to the brain, which can be life-threatening underwater. Vision abnormalities can include blurred vision or difficulty focusing, which can impair a diver's ability to navigate or respond to their surroundings effectively. Personality changes, such as confusion or irrational behavior, also occur due to reduced oxygen levels affecting brain function.

Because all these symptoms are valid manifestations of hypoxia and critically impact a diver's safety and decision-making capabilities, the most comprehensive answer is that all of the listed symptoms—unconsciousness, vision abnormalities, and personality changes—are indeed symptoms of hypoxia in diving. Recognizing any of these symptoms early on is crucial for taking immediate action to address the condition and ensuring the safety of the diver.