When breath-hold diving, hyperventilation will allow a diver to stay submerged longer by:

Hyperventilation before a breath-hold dive is known to reduce the carbon dioxide content of the blood. When a diver hyperventilates, they take rapid, deep breaths that elevate oxygen levels and significantly decrease the levels of carbon dioxide (CO2). This reduction in CO2 delays the body's natural urge to breathe, which is primarily triggered by increasing CO2 levels in the bloodstream.

As the diver holds their breath, the CO2 levels will increase over time, eventually reaching a point where the urge to breathe becomes overwhelming. By starting with lower CO2 levels due to hyperventilation, the diver can extend the time they can remain underwater before this urge forces them to surface for air. However, it is important to note that this practice must be approached with caution, as it can lead to shallow water blackout and other risks associated with altered gas levels in the body.

In this context, while the other choices might sound plausible, they do not accurately capture the primary effect observed with hyperventilation, which is the reduction of carbon dioxide content in the blood.