When would the relative humidity of an air mass increase?

when the air mass moved from a warm desert over a cold ocean
when water vapor is removed from the air mass and its temperature is increased
when the air mass passes from a cool forested upland to a hot savanna
when water vapor is removed from the air mass but its temperature remains the same
during hours between 7: 00 a. m. and 3: 00 p. m. on a typical summer day.

When the air mass moved from a warm desert over a cold ocean.

Explanation:

Relative humidity refers to the air´s water-vapor content relative to the temperature. Warm air is likely to have higher moisture, as it holds more water vapor than cold air. Therefore, the air has a higher relative humidity when the air gets cool, and lower relative humidity when is warmer.

Atmospheric cooling happens in different ways, including the movement of an air mass to a cooler area.