Which of the following assists divers in monitoring their Nitrox exposure?

The reasoning behind selecting dive tables as the correct answer lies in their fundamental purpose to aid divers in tracking their exposure to Nitrox during dives. Dive tables provide valuable information about the maximum allowable time at certain depths based on the level of oxygen in the breathing gas used. They help divers understand how long they can stay at specific depths without exceeding the data associated with Nitrox exposure limits.

This is essential for avoiding the risks associated with oxygen toxicity, which can occur when divers exceed recommended exposure levels to Nitrox mixtures. Thus, by using dive tables, divers can make informed decisions about their dive profiles, allowing them to monitor their exposure effectively throughout the dive.

While disposable depth gauges, emergency oxygen kits, and pre-dive briefings all play important roles in a diver's safety and preparation, they do not specifically assist in the ongoing tracking of Nitrox exposure during a dive. Depth gauges primarily indicate current depth, emergency oxygen kits are tools for first aid, and pre-dive briefings focus on dive planning and safety protocols rather than direct monitoring of Nitrox exposure. Therefore, dive tables are uniquely suited for this task, making them the correct answer.