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.

since there isn't any suggested answers i will give you the reason and hopefully you can figure it

south africa, or rather all of africa, has not been in the location in which it is nowadays throughout the geological past. after the super-continent pangaea started to break apart, gondwanaland, in which was africa, moved further south, and parts of it came to be very close to the south pole. because the climate in this part of the world is very cold due to the very dispersed sun rays in there, what is now south africa, started to freeze, and the conditions were right for the formation of glaciers. the glaciers existed up until the period when gondwanaland started to break apart and what is now africa started to move towards north, sp it warmed up and the glaciers melted.