What could happen to hot liquids during a rapid decompression?

The correct answer highlights a crucial physical phenomenon that occurs under rapid decompression. When the pressure surrounding a hot liquid drops suddenly, it can lead to a rapid decrease in the boiling point of that liquid. This means that the hot liquid, which is stable at a higher pressure, will start to boil violently due to the drastic change in pressure.

In conditions of low pressure, even liquids that are at temperatures significantly below their normal boiling point can start to vaporize due to the inability of the liquid molecules to stay in a condensed state. This can cause the liquid to erupt or boil over suddenly, which is particularly dangerous in scenarios like rapid decompression during flight.

The other options do not align with the physics of decompression. Hot liquids cooling quickly could happen under certain conditions, but the rapid boiling due to pressure drop is a more immediate and notable reaction. The idea of spilling unnoticed does not account for the boiling over that would be evident. Lastly, freezing would not occur in a decompression scenario of hot liquids, as the temperature would not reach freezing point due to the dynamics of heat transfer and the fact that the liquids are initially hot.