The correct answer is A. Increases.
The air’s capacity for water vapor is the maximum amount of water vapor that can be held in the air at a given temperature and pressure. As the temperature increases, the air molecules move faster and have more energy. This allows them to hold more water vapor. The opposite is also true: as the temperature decreases, the air molecules move slower and have less energy. This means that they can hold less water vapor.
The amount of water vapor that the air can hold is also affected by pressure. The higher the pressure, the more water vapor the air can hold. The lower the pressure, the less water vapor the air can hold.
The air’s capacity for water vapor is important because it affects the weather. When the air is saturated, it can no longer hold any more water vapor. This can lead to condensation and precipitation.