In what situation might air become saturated, resulting in condensation?

When the temperature and dew point are equal, the air reaches a state of saturation, meaning it can no longer hold all of the moisture in vapor form, leading to condensation. This process occurs because the dew point is defined as the temperature at which air becomes saturated with moisture, resulting in the formation of water droplets.

In meteorology, when air temperature drops to the dew point, it causes the relative humidity to reach 100%, prompting condensation to occur. This is often seen in situations where fog forms, dew settles, or clouds develop, illustrating the principle that saturation and condensation are directly linked to the relationship between temperature and dew point.

Other choices involve conditions that do not directly lead to saturation and condensation in the same way. Heating air or cooling it below freezing does not, by themselves, create the conditions needed for saturation, while a drop in humidity tends to lower the water vapor content, moving away from saturation rather than toward it.